It's so great that you are considering a vegetarian lifestyle! I have been a very strict vegetarian (no meat, fish, shell fish, etc.) for over ten years. I've been doing it so long and am so used to it now, but I know it can be hard to start out. And I admit, it can still sometimes be a challenge when going to family dinners, going out with friends, and on holidays like Thanksgiving. But you can get by: if you know people will not be eating veg-friendly food, you can always eat beforehand, or if you're going to a dinner you can bring a vegetarian dish for everyone to enjoy. Luckily there are a lot of restaurants that are veg friendly--most fast food places aren't, but that stuff's terrible for you anyway! But I can usually find at least one vegetarian item on any casual dining or sit-down restaurant menu. Then there are always sub shops and other sandwich type places that usually have some kind of veggie sandwich.
I have recently become interested in veganism; in fact my New Year's resolution this year was to have one day every week where I am 100% vegan (vegan Thursday!). I'd like to go totally vegan some day, but I know I may not have the willpower for it. But at least in the meantime I am cutting down on my intake of animal products. That is the best advice I can give: set realistic goals for yourself. It's much better reduce consumption of animal products and stick to it long-term than to set a goal that is just too difficult to keep up, that will just result in backsliding into a non-veg lifestyle.
Being vegan is much harder than vegetarian--I never knew how many products had dairy in them until I started this resolution! Veganism is also trickier nutrient-wise (vegetarians can easily get all of the nutrients they need from food, but vegans MUST take B-vitamin supplements, as animal products are the only foods that have it in high enough concentrations). But these days, vegetarianism isn't that hard if you really dedicate yourself to sticking with it. Vegetarians have tons of options now more than ever. For example, Trader Joes and Whole Foods are great places to find frozen or pantry meals for days when there is no time to cook. Just make sure you read ingredient labels. The hardest part for me is definitely figuring out what ingredients that don't seem animal based really are (for example, gelatin is made from animal bones, some beers use fish swim bladders in the filtration process, rennet--an ingredient found in many cheeses--is made from cattle by products, etc).
I used to have a subscription to a magazine, Vegetarian Times; they have a website with a lot of recipes. There are a lot of great vegetarian recipes and cookbooks out there. I'm still on the lookout for a really good vegan one since I'm new to trying out the vegan thing. So if anyone else has any recommendations I'd be happy to hear them! (Oh, and about vegans and bread...yeast is similar to mushrooms--not animal-based. So as long as the bread was made without dairy, honey, eggs, lard, etc., bread is perfectly fine for most vegans). There are all kinds of meat substitutes (tofu, tempeh, seitan), as well as store-bought foods that use these meat subtitutes (Gardenburger, Boca, Morningstar Farms, Match, Tofurkey, etc.)
Also, if you're interested in cruelty-free shopping, PETA (I have some issues with PETA, but I still find this resource valuable) has a list of brands/companies
that are cruelty-free, as well as a list of known animal testers. The list is far from comprehensive, but it does list quite a few brands.
I wish you the best of luck in trying out vegetarianism/veganism; you won't regret it! Let me know if you have questions!