Get him involved in recreation leagues first, then after a couple of years let him pick his favorite or favorites to play competitively, if he wants.
Baseball
Basketball
Track
Cross-Country
Swimming
Football
Hockey
Wrestling
Soccer
There is a list of all sports ten year old boys might like....
first of all, male/female and your age
Harry Potter or Twilight (please explain with a legitamate reason, not just "its better" etc)
JK Rowling or Stephanie Meyer? (which one writes better, not just which wrote the book you like better! Who actually wrote a more cant-put-it-down intense...