For broad brush planning, go to JimBsail.info . The page which follows that link covers Portugal. Or find the pages by googling "jimb portugal" - an easy solution to finding and European on-line cruising guides
I found The Cruising Association Almanac gave adequate coverage for piloting the area, but the guides referred to in earlier posts give more background information. Whichever you get, if you don't have a local bookshop, you can order on-line through the web site Book Shop. The discount nearly pays for the delivery costs!