I'd say I'm flexitarian. I do eat vegetarian quite a few days of the week, but I'm not strict about it. I've been trying to only eat meat products mindfully. For example, we used to put boneless skinless chicken breast in many meals that would've been fine as vegetarian meals (this is mostly due to DH's preferences). Lately, I've only been eating meat if it's really delicious and adds something to the meal. I find chicken breast to be pretty tasteless, so it was easy to give it up. DH still eats deli meat, but I've mostly given that up too since I don't find it that tasty. I also get almost all of my eggs from a friend and buy local organic milk. My goal is to do as bunnyfriend does and only eat meat from local, humane sources - I'm working on that, but I live in an area with a lot of farms so the more I learn about the area the easier it becomes.
It seems strange that adding poultry back to your diet would cause weight gain - it's generally pretty low-cal. I don't find vegetarian food to promote weight loss anyway, since it's easy to eat just as many calories of a delicious veggie pasta dish as it is with a pasta dish containing sausage or something, ya know? Though if someone's non-vegetarian diet is steak and potatoes and their vegetarian diet includes tons of veggies, then I can imagine they would lose some weight.
I just got a new veggie cookbook - Vegetarian Cooking for Everyone by Deborah Madison. I'm liking it so far and it's a nice addition to my other veggie and non-veggie cookbooks. The cookbooks from Moosewood Restaurant are also a favorite and I grew up with my mom cooking from them.
Equalsign, I agree with you that being vegetarian doesn't require a ton of research. Vegan probably requires more, but generally if you eat a wide variety of foods, including fruits and veggies of all colors, you'll be fine. I think sometimes overemphasizing the research aspect makes people think they could never be vegetarian and keep track of so many things in their diet, but it's really just as easy as being an omnivore for the most part.