iphone data plan with rogers!!!?

Hi i am planning to get an iphone with rogers along with 500 mb data plan...i was just wondering if that would be enough? i will mostly used it to browse rather than emailing and downloading...and i have wireless network at home...would it be possible for me to connect to my wireless network at home and not use the 500 mb and can i do that at school too...i have wireless access there as well...i am new to all of this...plzz help

thank you