One of the hardest parts about venturing down the vegetarian or vegan path, is knowing where to start. Luckily there are many great people out there who have put together some really helpful "how to guides."
Gives a short but sweet starter guide complete with nutritional information, environmental and animal rights facts, and some amazing recipes. Try the Neapolitan Bars, they're amazing! Plus, several of the staff members share their reasons for going veg. Giving this kit a great personal touch.
Has both an online version as well as a print version available. The online version has a quiz, videos, weight loss and diet change information, great recipes for making the transition, as well as testimonials from celebrity members. They also include a link to HappyCow to aid new vegetarians and vegans in finding restaurants.
The Humane Society provides a comprehensive guide on going vegetarian. They go into a fair amount of detail about factory farm conditions. The guide also includes excellent nutritional and environmental impact information. Though their shopping guide is mostly aimed at those looking for animal product replacements, they do include a glossary of foods such as seitan and tempeh that non-vegetarians might not already eat.
Vegan Outreach's guide is available both online and in print. They even give you the option of ordering several copies to spread the vegan love. They offer a vegan foods glossary, substitution tips, recipes and a great FAQ. Their guide also offers a great list of organizations, and discussion groups, to make finding other vegans easier.
The Vegetarian Starter Kit from the Physicians Committee for Responsible Medicine is the most comprehensive guide I've seen. They offer information for being vegetarian during pregnancy, how to raise children vegetarian, debunking myths, how to achieve and maintain a healthy weight, and give a three step plan for how to get started. You also have the option to print handouts as well as have them send a print copy of the guide to your home.
Mercy for Animals
Mercy for Animals offers both a print copy you can send away for as well as a pdf version. The pdf starts off with a letter from their Executive Director, Nathan Runkle, explaining how he became vegetarian. They offer plenty of detailed information on factory farming practices as well as the agricultural impact it creates. They have a copy of the vegetarian food pyramid in the nutritional section. The kit also provides meal ideas for those just making the switch as well as several recipes. Try the Pumpkin Patch Cheesecake, its a personal favorite!
The Humane League
The Humane League offers informative links that will help you easily eat on the road. Many of their links are to other groups on this list, which makes this a nice catch all for the best info. They also link to the video, Farm to Fridge, which gives a good look into the brutal world of animal agriculture. There is also a magazine style kit that you can register to have sent to your home.
Of course don't forget to check out TDIV's Guide to Going Vegan: The Realistic Method.