I live about 30 minutes north of Portland and can give you limited advice. First off, you'll be right next to a
Rich's Cigar Store in the Pearl. Here's a
map of the three locations they have. "B" on the map is the one in the Pearl. I've only been to the one on Alder Street and I hear that it's the best and biggest of the three. Second, which is where you should really try to make it, is Steven Books'
House of Calabash in Oregon City. To be honest, I've never been there myself, (although I'm taking an opportunity to go there this afternoon while down that way on some separate business) but if you have ever heard talk of this guys talents you really need to try and make it there. Here's
directions from Rich's in the Pearl to House of Calabash in Oregon City.
Anyways, hope that's of some help and have a fun time!
Edit
ops, looks like the directions link isn't working. Here's the location of
House of Calabash