If you have the Champions genre book, I recommend monkeying around with the random character-generator in there. It's not without it's flaws, but it will turn out some pretty serviceable characters, and the simple process of getting to know how the random generator works will teach you a good deal about character design.
Since you mentioned you were interested in a basic speedster character, here's one I came up with on the fly, using a combination of the random generation system and my own experience. He's meant to be a pretty generic speedster. His powers are theoretically derived from knowledge of a particular mystical martial art, but he's not built like a traditional martial artist (no martial arts maneuvers). Instead, his abilites manifest themselves as incredible speed and toughness, the martial arts angle is really just a special effect.
Sadly, he can't hit super-sonic speeds. His maximum non-combat running speed translates to about 156MPH (or 252 KPH). If you're really sold on the concept of super-sonic speed, subtract 10 points out of the character somewhere and buy 2 levels of non-combat multiplier on his running. That'll get him up to better than 1200 MPH, which should be sufficient. I recommend ditching the Speed-Reading and reducing the 'Toughness' power to 3pd/3ed of damage resistance if you want to go that route.
<font size=+1><b>Wind Dragon</b></font>
Player:
<table cellpadding="0" border="0"><tr><td align="right"><font size=2><b>Val  </b></font></td><td><font size=2><b>Char   </b></font></td><td><font size=2><b>Cost</b></font></td></tr><tr><td align="right"><font size=2>20  </font></td><td><font size=2><b>STR</b></font></td><td><font size=2>10</font></td></tr><tr><td align="right"><font size=2>23  </font></td><td><font size=2><b>DEX</b></font></td><td><font size=2>39</font></td></tr><tr><td align="right"><font size=2>20  </font></td><td><font size=2><b>CON</b></font></td><td><font size=2>20</font></td></tr><tr><td align="right"><font size=2>12  </font></td><td><font size=2><b>BODY</b></font></td><td><font size=2>4</font></td></tr><tr><td align="right"><font size=2>15  </font></td><td><font size=2><b>INT</b></font></td><td><font size=2>5</font></td></tr><tr><td align="right"><font size=2>14  </font></td><td><font size=2><b>EGO</b></font></td><td><font size=2>8</font></td></tr><tr><td align="right"><font size=2>10  </font></td><td><font size=2><b>PRE</b></font></td><td><font size=2>0</font></td></tr><tr><td align="right"><font size=2>10  </font></td><td><font size=2><b>COM</b></font></td><td><font size=2>0</font></td></tr><tr><td><font size=2></font></td><td><font size=2> </font></td><td><font size=2></font></td></tr><tr><td align="right"><font size=2>15/41  </font></td><td><font size=2><b>PD</b></font></td><td><font size=2>5</font></td></tr><tr><td align="right"><font size=2>15  </font></td><td><font size=2><b>ED</b></font></td><td><font size=2>5</font></td></tr><tr><td align="right"><font size=2>7  </font></td><td><font size=2><b>SPD</b></font></td><td><font size=2>27</font></td></tr><tr><td align="right"><font size=2>12  </font></td><td><font size=2><b>REC</b></font></td><td><font size=2>8</font></td></tr><tr><td align="right"><font size=2>40  </font></td><td><font size=2><b>END</b></font></td><td><font size=2>0</font></td></tr><tr><td align="right"><font size=2>35  </font></td><td><font size=2><b>STUN</b></font></td><td><font size=2>3</font></td></tr><td><font size=2></font></td><td><font size=2> </font></td><td><font size=2></font></td></tr><tr><td align="right"><font size=2>30"  </font></td><td><font size=2><b>RUN</b></font></td><td><font size=2>0</font></td></tr><tr><td align="right"><font size=2>2"  </font></td><td><font size=2><b>SWIM</b></font></td><td><font size=2>0</font></td></tr><tr><td align="right"><font size=2>4"  </font></td><td><font size=2><b>LEAP</b></font></td><td><font size=2>0</font></td></tr></table><b>Characteristics Cost:</b> 134
<table border="0" cellpadding="0"><tr><td align="right"><b>Cost  </b></td><td><b>Power</b></td><td align="right"><b>END</b></td></tr><tr><td align="right" valign="top">60  </td><td>Running +24" (30" total), Reduced Endurance (1/2 END; +1/4) (60 Active Points) </td><td valign="top" align="right">2</td></tr><tr><td align="right" valign="top">40  </td><td><b><i>Speedster Powers: </i></b>Multipower, 40-point reserve </td><td valign="top" align="right"></td></tr><tr><td align="right" valign="top">2u  </td><td>1) <b><i>Impact Resistance: </i></b>Armor (26 PD/0 ED) (39 Active Points); Only Works Against Limited Type Of Attack (Very Limited Type of Attack; -1) [<b>Notes:</b> Only vs. damage sustained by performing move-bys/move-throughs] </td><td valign="top" align="right"></td></tr><tr><td align="right" valign="top">3u  </td><td>2) <b><i>Rapid-Fire Punch I: </i></b>Hand-To-Hand Attack +8d6 (40 Active Points); Hand-To-Hand Attack (-1/2) </td><td valign="top" align="right">4</td></tr><tr><td align="right" valign="top">2u  </td><td>3) <b><i>Rapid-Fire Punch II: </i></b>Hand-To-Hand Attack +5d6, Autofire (5 shots; +1/2) (37 Active Points); Hand-To-Hand Attack (-1/2) </td><td valign="top" align="right">4</td></tr><tr><td align="right" valign="top">4u  </td><td>4) <b><i>Friction Attack: </i></b>Killing Attack - Hand-To-Hand 2 1/2d6 (plus STR) (vs. ED) (40 Active Points) </td><td valign="top" align="right">4</td></tr><tr><td align="right" valign="top">1u  </td><td>5) +1 SPD (10 Active Points); Costs Endurance (Costs END Every Phase; -1/2) </td><td valign="top" align="right">1</td></tr><tr><td align="right" valign="top">8  </td><td><b><i>Wall-Running: </i></b>Clinging (normal STR) (10 Active Points); Limited Power (Power loses about a fourth of its effectiveness; -1/4) [<b>Notes:</b> Only during phases in which the character performs at least a Half Move] </td><td valign="top" align="right"></td></tr><tr><td align="right" valign="top">9  </td><td><b><i>Toughness: </i></b>Damage Resistance (9 PD/9 ED) </td><td valign="top" align="right"></td></tr><tr><td align="right" valign="top">6  </td><td><b><i>Momentum: </i></b>Knockback Resistance -4" (8 Active Points); Limited Power (Power loses about a fourth of its effectiveness; -1/4) [<b>Notes:</b> Only during Phases in which the character performs at least a Half Move] </td><td valign="top" align="right"></td></tr><tr><td align="right" valign="top">12  </td><td><b><i>Situational Awareness: </i></b>Enhanced Perception (+4 to PER Rolls for All Sense Groups) </td><td valign="top" align="right"></td></tr></table><b>Powers Cost:</b> 147
<table cellpadding="0" border="0"><tr><td align="right"><b>Cost  </b></td><td><b>Skill</b></td></tr><tr><td valign="top" align="right">10  </td><td>+2 with HTH Combat </td></tr><tr><td valign="top" align="right">5  </td><td>Defense Maneuver: I-II  </td></tr><tr><td valign="top" align="right">5  </td><td>Tactics 13- </td></tr><tr><td valign="top" align="right">3  </td><td>Acrobatics 14- </td></tr><tr><td valign="top" align="right">3  </td><td>Breakfall 14- </td></tr><tr><td valign="top" align="right">2  </td><td>KS: Wind Dragon Kung Fu 11- </td></tr><tr><td valign="top" align="right">3  </td><td>Analyze: Style 12- </td></tr><tr><td valign="top" align="right">2  </td><td>WF: Common Martial Arts Melee Weapons </td></tr></table><b>Skills Cost: </b>33
<table cellpadding="0" border="0"><tr><td align="right"><b>Cost  </b></td><td><b>Perk</b></td></tr><tr><td valign="top" align="right">2  </td><td><i>Grace Law, cub reporter:</i> Contact 11- </td></tr></table><b>Perks Cost:</b> 2
<table cellpadding="0" border="0"><tr><td align="right"><b>Cost  </b></td><td><b>Talent</b></td></tr><tr><td valign="top" align="right">15  </td><td><i>Super-fast Perceptions:</i> Danger Sense 12- </td></tr><tr><td valign="top" align="right">12  </td><td>Combat Luck (6 PD/6 ED) </td></tr><tr><td valign="top" align="right">4  </td><td>Speed Reading (x10) </td></tr><tr><td valign="top" align="right">3  </td><td>Lightning Reflexes: +2 DEX to act first with All Actions </td></tr></table><b>Talents Cost:</b> 34
<b>Total Character Cost:</b> 350
<table cellpadding="0" border="0"><tr><td align="right"><b>Val  </b></td><td><b>Disadvantages</b></td></tr><tr><td valign="top" align="right">10  </td><td>Physical Limitation: Must Maintain a Special Diet or powers are lost (Infrequently; Greatly Impairing) </td></tr><tr><td valign="top" align="right">20  </td><td>Psychological Limitation: Code vs. Killing (Common; Total) </td></tr><tr><td valign="top" align="right">15  </td><td>Psychological Limitation: Protective of Innocents (Common; Strong) </td></tr><tr><td valign="top" align="right">10  </td><td>Psychological Limitation: Honest, won't tell a lie without a good reason (Common; Moderate) </td></tr><tr><td valign="top" align="right">15  </td><td>Social Limitation: Secret Identity (Frequently; Major) </td></tr><tr><td valign="top" align="right">20  </td><td>Vulnerability: 2 x STUN Gas/Poison (Common) </td></tr><tr><td valign="top" align="right">5  </td><td>Rivalry: Professional (Kinetik), Rival is As Powerful, Seek to Outdo, Embarrass, or Humiliate Rival, Rival Aware of Rivalry </td></tr><tr><td valign="top" align="right">15  </td><td>Hunted: Green Dragon 11- (As Pow; Harshly Punish) </td></tr><tr><td valign="top" align="right">20  </td><td>Hunted: The Triads 8- (Mo Pow; Harshly Punish; Extensive Non-Combat Influence) </td></tr><tr><td valign="top" align="right">15  </td><td>Physical Limitation: Hyper-reflexes, uses powers unintentionally (Frequently; Greatly Impairing) </td></tr><tr><td valign="top" align="right">5  </td><td>Distinctive Features: Unique dragon tattoo covering arms, shoulders, upper chest (Easily Concealed; Noticed and Recognizable; Detectable By Commonly-Used Senses) </td></tr></table>
<b>Disadvantage Points:</b> 150
<b>Base Points:</b> 200
<b>Experience Required:</b> 0
<b>Total Experience Available:</b> 0
<b>Experience Unspent:</b> 0
His Hunted (Green Dragon) and Rival (Kinetik) appear in Champions and Millennium City, respectively. If you don't have those books, then subsitute any martial artist and speedster into those roles.
Once you've got your feet under you, you might want to take a look at this thread. http://www.herogames.com/forums/showthread.php?s=&threadid=2730
While it's primarily about ways to save points, and I definitely don't recommend following all of the advice you might find in there, it can give you some idea of what different people consider important steps in the character design process.