If you go to amazon.com, you will find loads of books on vegetarian, vegan and raw diets. You can also get some of the same books at the library, so it is not information you can only find on the internet.
Your doctor can also give you his or her opinion about that kind of diet.
Bill Clinton did lose a substantial amount of weight by becoming a vegan (he does eat one fish meal a week, though). He has chefs and doctors helping him out with any questions of planning he needs to do to maintain that lifestyle. We should all be so lucky!
It's your health, not just your weight, so get the most help and information you can possibly find. Good luck!