G.C.
I second Wholesomebabyfood.com, that's a great resource. Not sure if you're using ready made jarred food or making your own, but either way you can check out the selection of jarred food at the store to see what ingredients are appropriate at which age.
There are lots of good books on making homemade baby food, but many of them have inaccuracies on what to introduce when, like telling you to introduce eggs or nut ingredients before age 1. You can try giving your 7 month old egg yolks like from a hard boiled egg, but not the white which contains the protein (that's the allergenic part).
My top 2 books on baby food are Super Baby Food by Ruth Yaron and Superfoods for Babies and Toddlers by Annabelle somebody. Super Baby Food is no frills but very comprehensive with household hints, tips to save money, and even arts & crafts. Superfoods for Babies and Toddlers has nice glossy photos. You could read the detailed reviews on Amazon or look for them at your local library. But again, I wouldn't go by everything in these books for what to introduce when.
For your baby's first year, things you need to avoid include honey, corn syrup, maple syrup, egg whites, nuts, shellfish. If either parent has a food allergy, then avoid that food. Talk to your pediatrician about all this but you can try yogurt at 6 months old as long as you don't suspect any issues with dairy. For meat, I'd wait until 9 months. Good luck and let me know if you want to correspond more about any of this.