Tonight I am going to take shots of my nephew's football game. I've never taken sports/action shots so I'm not expecting thrilling shots but thought I would ask for any tips for a noob. I have a Canon XSi. I need to decide between two lens. I have the 70-300mm 4-5.6 (I think this is correct) and the 24-105mm 4.0L. The game will be at night on a well lit field. I've read some tips already but would appreciate any extras. This is the first game of the season so I hope to practice to get some keepers for my parents and nephew for memories. Thanks in advance.