You'd be surprised what they could eat.

Yes, you should feed carpet pythons rats from birth to death (though big ones can take guinea pigs, rabbits etc).

I order my frozen rat pinkies online. There are a number of places you can do this from.

Rodentpro.com is a big name.

I ordered from a guy off of kingsnake.com who had slightly better prices, but I think next time I'll go with rodent pro as I've had issues with quality in packaging.