How to loose weight!?

okay i am 5'4 and i weight 120 pounds. well i wnat to get into good shape so i have to been for the past 3 weeks working out every day and eating really healthy. but here and there i would eat a few chips or stuff like that. does that efect it at all? i am not getting good results from this. can you guys tell me any good work out things or stuff that is good to eat or whatever. beucase i need to be in good shape for snowboarding this winter. thanks in advance.