Clubs and pubs in Edinburgh: several.
The pubs that have folk music every night are The Royal Oak, Infirmary Street, Captain's Bar in S College Street,and Sandy Bell's in Forrest Row: all quite close to each other, so you can drift between. Others have maybe one night a week, or a varying programme throughout the week, so try to pick up a copy of the "Gig List" in any music bar you go to.
I think Edinburgh Folk Club kicks off again after summer break in mid-Sept (?16th) -every Wednesday, and Newtongrange Folk Club is every Thursday - a bit further out of town, but on a bus route! Singers' night in No 1 on The Royal Mile also on Thursday evenings, and varying styles of music in the Whiski Bar on the Royal Mile each night if the week. Also sessions in The Antiquary on St Stephen's St, Stockbridge on Thursdays.