I've been a vegetarien for, hmm, about 15 years. I started when I was 6 or 7 (I think I was inspired by Charolette's Web, my parents are not vegetariens at all.) I'm not vegan, I don't eat any meats including chicken, Turkey, or fish but I do eat honey and eggs and drink milk. (Although I wish they would treat animals better and I don't see how anyone could disagree with that.)
Anyways, I exercise moderatly and actually don't eat too too healthy, but I think I'm pretty healthy compared to some of my friends... (I'm 160lbs. btw)
If you ask me, the key to a vegetarien diet is developing a taste for non-meat foods. Even after all this time it still really sucks for me when I go to, say, a buffet and there's maybe 2-3 foods I can eat and a bunch of tasty looking meat etc. that I can't touch... but it's not so bad if I really love those 2-3 things. Of coarse it also takes some determination and Will Power. I used to love shrimp. It was my favorite food before I stopped eating it. I guess I could say that I still miss it, but I will absolutly not eat it.
So I'll just tell you about my diet:
I eat lots of pasta. Not too healthy but I love it. I use Ragu Sauce and Parmasean cheese. I also like Eggplant Parmasean. (Not too big on Italiten foods.)
Like people have been saying, ToFu. It's awesome, I love it so much now I could just eat it plain. It's best mixed in with stir-fry though imo but it's just good prety much any way you serve it.
Speaking of.. stir fry! Vegetables or whatever else you can get in there. Various sauces like Teriyaki, I eat that a lot and it's actually pretty easy to cook (Although messy.)
Most TV Dinners have meat but there are a few that don't. They're not too good for you either but they're easy.
Concerning faux meat products, here in the states, Morning Star Farms is the best brand in my opinion. (Boca burgers are definatly the best veggie burger though) They also have a real lot of selections available, from soy protein veggie sausages (They're really good) to soy protein chicken or beef strips (Which I put in stir frys.) Oh, and their veggie ground beef is amazing too. I use it in Tacos and veggie chilli, or I could jsut eat it plain. The downside is how expensive they are... But as a vegetarien I look at them as occasional treats.
You should definatly try Hummus, it's really great. I like to dip pieces of Matzah (or whatever cracker you prefer) into it. There's a variety of flavors too. Go to a Middle Eastern kinda resturaunt and get a falafel (Deep fried hummus in a pita) and you'll see just how great hummus is!
Sushi is really great. Most of it has fish in it yes, but there's plenty of selection for me when I go to a (good) sushi resturaunt. Beyond plain avacado rolls, there's cucumber, carrot, vegetable tempura (in rolls and by itself,) mango (if you dare,) mushroom and roots. Also, Inari and Egg Custard Sashimi.
I drink Vitamin Water and normal water a lot, and usually a cup of juice every day. However, my favorite drink is Soy Milk. At first I tried it it seemed chalky but I quickly developed a taste for it and it's now my favorite drink. I recommend Silk or Pearl brand. Stop & Shop brand Nature's Promise is a more affordable tasty brand too.
Well, those are most of my favorite things. Besides those I eat everyday things like sandwhiches, cereal, rice(I prefer brown rice, it's better for you too,) and whatever meatless things I can get my hands on.
Oh yeah, and if you didn't already know avoid Trans Fat. From what I hear it's like, pretty much the worst thing for you. Trans fat comes from Hydrogenated Oils, and about two years ago the U.S. food people (Whatever they're called) passed a law saying that products must display how much trans fat are in things (It was previously not shown, but they finally realized how bad it was for you and forced companies to show this. That's why all food labels have Trans Fat listed on them now.) However! If there's just a tiny amount of trans fat in something they round it down to zero. I'm not dietician, but from what I've heard it's best to just avoid everything with Hydrogenated or Partially Hydrogenated Oils in it.
I suppose it's significant to note that in all this time since I was a child I've never had any sort of health issue concerning my diet (such as lack of protein or Iron) and I've never consulted any sort of diet doctor on the matter either, Perhaps I was lucky or my body adaptaed or something but I just don't worry about those things.
Finally, although you're becoming a vegetarien for health reason and not moral reason so this is probably irrelavant to you, but just pointing it out. Many products (Jello, Marshmellow, some candy, random tv dinners) have geletin in them, which comes from animals (Boiled animal fat with water I believe?) Also, some Romano cheese has Rennet in it. And some Rennet comes from Sheep's stomachs (Some doesn't however.) While health wise these small little ingrediants of meat probably don't do anything, I avoid them because you have to kill them animal to get them.
Good luck in your health endeavors!