I've been a Vegetarian for over six years--Vegan for the past year, year and a half of it.
I agree with Kenicki minus the fake meats--Most aren't Vegan. Not sure if you're talking about simply being Vegetarian, Kenicki, but you might want to check your labels. And yogurt isn't Vegan either... Neither is most granola. Anyways.
If you make sure you eat enough calories (as many people use Veg'nism as a cover up for eating disorders) and most of those calories are vegetables, you shouldn't have to worry about deficiencies.
Oh, and
this thread may give you some tips, though it's about Veganism, not Vegetarianism.
Lastly, if anyone is wondering, Vegans do not eat
any animal products. That includes but is not limited to meat, fish, seafood, eggs, dairy, milk, cheese, yogurt, gelatin, rennet, honey, ... Vegetarians do
not eat animals, including meat, fish, seafood, pork, beef, chicken, turkey, birds, gelatin, rennet, ... Some may chose to eat dairy and/or eggs.