Guimarães being nominated as European Capital of Culture in 2012 is well worth visiting. The tourist information is already documented (7 languages) with beautiful free booklets, describing all the monuments. The historic centre is very easy to walk and a delight because it is almost car free.
Apart from the trip report: tripadvisor.com/ShowTopic-g189180-i598-k4461… I would like to add that I went to Guimaraes by Arriva bus from Porto. As it was not easy to find the bus information I'd like to share it here with you: http://www.arriva.pt/horarios/ and click on Fafe - Guimaraes - Porto (Rapida via Auto Estrada), line 500 This regular bus service brings you in 50 min. to Guimaraes bus station. From there the (slightly uphill) walk to the historic centre was only 8 minutes. A return ticket costs just over 9 euro. The bus station is close to Trinidade metro, just a 2 minute walk up the road.
Right in the historic centre opposite the town hall (once Convent of Santa Clara, nr. 8 in the booklet), I found this lovely little restaurant for lunch. Inside it looks like a cafe with 5 tables but it has a huge garden at the back and a nice dining room upstairs. The warm weather permitted me to have lunch on the front balcony, adjacent to the dining room on the first floor. A small balcony with a handful of tables. I had delicious grilled fish (dish of the day is Euro 6,--) , various types of bread, great olives and the service was very attentive. A real hidden gem. The name of the restaurant is Art & Gula.
Hope this helps.Edited: 9:36 am, September 22, 2011