Kid's Birthday

[Avikar]

I am not sure if this is the area to put this on the fourms or not. did not see a questions section.

On Saturday my daughter will be attending a birthday party. The party will take place in a indoor playground/gym.

I have a rebel xs with the 18-55mm kit lens and a 50mm 1.8. Just wondering if anyone has any hints/tips for dealing with fast moving children. I am thinking of using the 50mm due to its fast shutter times. My question is what is a good aperture for general shots like this where I can get a ok depth of field but with a shutter speed fast enough to catch the action and deal with camera shake since this being a party I will be moving around alot.

Any tips would be greatly appreciated.