It's hard to grow grass under large old Oaks I would mulch around them then depending on your preference and dedication to lawn maintenance you could aerate and seed with Bermuda. During the spring Bermuda can be seeded but not Fescue you'll have to wait until the fall to aerate and seed Fescue. If you plan to go with Bermuda you may want to look into getting the yard sodded. If your looking to have a green yard now and don't want to sod it will be a bit of an undertaking. First you'll have to scalp the yard then aerate seed and top dress plus fertilize with 1-0-1 ratio to start. This is if you plan to use Bermuda. For fescue wait till fall and scalp the yard aerate seed and top dress.

No seeded grass is going to work for you. The only grass type that can grow in light to moderate shade is Saint Augustine, and that is from sod only. Forget Bermuda in shady areas.

Also note NO GRASS will grow in deep shade. Sorry but those are the facts.

Where do you live?

Can you post a picture of your oaks casting a shadow on the yard? My front yard is under a canopy of oaks but I grow St Aug just fine. But my canopy is up about 30 feet high so my shade is not considered to be that deep.

http://forums2.gardenweb.com/forums/load/lawns/msg0510183120465.html

Tifgrand bermuda in shade. See link above for non-biased opinion... I like the 5-6 week update with pics.