Howdy, and welcome to the site.
If you're looking to lose that much weight, start off with small steps, but be consistent.
For nutrition, I think this is a great step-by-step article:
For training, really almost any program that has you lifting weights three or four days a week and doing cardio two or three times a week would be a great start.
Do you have any kind of experience with exercise - in college, previous attempts to lose weight, etc.?