Include whole grains, legumes, vegetables, fruit, nuts, and seeds. Most people that switch to more vegetarian options forget about protein sources. Be aware that these foods may add more saturated fat to your diet unless you are choosing the fat free or lower fat forms. The strongest proteins in a strict vegetarian diet are the legumes, nuts and seeds. Speaking of soy, you are probably hearing about the health benefits of soy products relative to heart and bone health.
Soy comes in a variety of forms.
You can choose soy milk, soy flour, soy protein powder, tofu, tempeh, soy nuts, textured vegetable protein, etc. If you are interested in soy cooking, there are some helpful cookbooks available. Another resource for information about cooking with these foods is your local health food store. Many of these products used to be difficult to find, but many are now on the shelves of your grocery store. Items such as soy cheese, tofu hotdogs, and soy sausage may be lower in fat than the more traditional product.