I am headed there in May and want to hit the different AVA's and get the wines that are particular to that region. I am hoping someone can give me some suggestions as to what wineries to hit for specific wines. Such as I am going to go to Staggs Leaf and pick up one of their Cabs. I will be in Napa for a day and Sonoma for a day.

There's a thread in the Wine Conversations section about this. Use the search function and you'll find plenty of info.

BTW - Do you mean Stags Leap Wine Cellars?