Need to loose it again... Please Help!!!

A few years ago (probably about 4) I went from 260lbs to 200lbs in about a year...now I am back up 225lbs...I let it sneak back up on my and now I must do it again...to get myself in the gym at least a couple days a week i signed up for a half marathon in nov (Philly half marathon)...just coming back here for some inspiration and general comments or helpful hints...

Thanks guys!!!