Decks, Patios, Porches and Docks - Ground level deck, anchored to the foundation?

I have an existing slab that is 8'x8' and cracked into three pieces. My plan is to remove the slab and replace with a 12'x 30' wooden deck across the back of the house. Due to the elevation and size of the surrounding yard the deck needs to be ground level and against the house. One additional problem is the right angle corner that the house makes where the deck will be. In that corner there should be a post for support, correct? I have read in other posts that it is not advisable to dig any holes at the foundation, but with the clay in the soil here in Texas I have to secure it somehow to keep it from shifting over time. Any advise on how to provide stability in a corner like that? Also, if I dig out the soil to place the ledger boards against the foundation, what is the best way to secure them too the concrete? Expansion bolts?