One cookbook that has been very helpful to me is "Moosewood Restaurant Cooks at Home." All the recipes are vegetarian and geared to be cooked in a short time (about half an hour) with common ingredients. While it's not lacto-ovo, or even celiac, most of the recipes are useful as is or very adaptable. For instance, cheese is often an optional ingredient, and even the pasta sauces can be served over polenta or millet. The great thing about this book is that the recipes are easy to cook, quite tasty and varied. With all of the beans, alternate grains and tons of vegetables, you don't have to worry about protein.
Also, check out your local asian market for noodles made of rice, tapioca, beans or cornstarch. These have been a real lifesaver!