Since you're still 17, living with your mother, it can be difficult. Try talking with your mother about why you want to go vegan. Research more on the benefits, and present your case, so to speak. Don't be argumentative about it, though. Keep in mind that she will probably think this is just a "late teen rebellious" stage. You can nip this in the bud by addressing this issue.
As far as what to eat, simply cutting meat and dairy is a start. GoVeg.com is a good place to begin looking at vegan alternetives. Click "Recipes" there. PETA is many things, but "withholder" of information, they an't.
There's also plenty of meat replacements. I... used to eat Chik'n Patties from Boca.
As far as milk, research and see how much better for you soy milk is for you, and how it can give you the same "benefits" that doctors tout cow milk to give you.
Good luck!
