Method #1 Go to your contacts list in the "People" app. Scroll through and find the name of the person you want to delete, long press that contact until the menu pops up, then choose Delete...or just click the person to bring up their "contact card," press Menu button, and choose Delete.
Method #2 If you have a Google Account (which every Android user should) then hop on your PC/Mac/Linux box, log into Gmail.com and click "Contacts" on the upper left. If your phone has contacts sync'd then every name on your phone will be in this list. Just find the names you want to get rid of, check the box next to the name on it's left, then click "More actions" at the top and choose Delete. This technique allows you to delete multiple contacts and save some time.
