You'd be amazed at what they can mash even with no teeth! And many "normal" foods can be turned into something they can easily eat with a hand mixer or food grinder.
I think the key is to keep trying new things but at a pace where you can detect any food allergies (only one new food every 4 days or so).
Some things my son ate then:
real oatmeal, applesauce, soft cooked veggies (carrots, potatoes--sweet and white, peas, green beans, squash, etc), yogurt, cheese, crackers, pancakes, eggs, tofu, most soft fruits--i just avoided apples, raisins and uncut grapes.
If you are looking for recipe ideas, I really love the book:
Superfoods for Baby and Children by Annabel Karmel (http://www.amazon.com/Superfoods-Babies-Children-Annabel-...)
I still use it for my two year old to get ideas of new things to make...