i'm vegan and i use supplements sometimes, but only because i have some around and i hate to waste. i've been vegan 3 1/2 years or so and vegetarian for 14.
anyway. just be sure you're getting a nice variety of stuff. veggies and fruits of different colors and some healthy carbs and you can have beans and tofu and tempeh and seitan. my fav vegan site with tons of recipes and ideas and pics of food to inspire you is Post Punk Kitchen Forums: Show us your mitts!
also, lots of cheeses aren't even vegetarian (they have rennet - from animal stomachs!) so beware of that.