I will be traveling July 20-August 8 in the Basque region of northern Spain. Any suggestions of what not to miss in Pamploma and Bilbao as well as any towns around that area.
Rick's Spain book covers, Pamplona, Bilbao, and other stops, but not Logrono. All have old town areas and the Guggenheim Bilbao art museum is a top architectural destination regardless of what exhibits are currently offered inside.
I found this article about a tapas crawl in Logrono to be inspiring, but did not end up seeing that city on my way to Burgos and Leon.
As well as the places you mention - San Sebastian, Bilbao, Vitoria, Logrono, Pamplona - make sure you get to Guernica and the Peace Museum. http://www.museodelapaz.org/en/index_en.php
Just south of Pamplona is the town of Olite. There is a great castle there worth visiting, one of my personal favorites anywhere. It's partially restored but not furnished so you can explore at will with an included audio guide that describes the castle when the Kings of Navarre (this part of Spain and part of France) were there.
Along the north coast should be good this time of year. I liked San Sebastian (Donostia is the more correct local name for the town), but it was cold in April and clearly needed to be visited during the hottest part of summer - so we didn't explore that coast any further on our trip. I've heard great things about Santander.