This article is from the Real Ale FAQ, by with numerous contributions by Brett Laniosh others.
A: The "Good Pub Guide", although its primary aim is to direct people to
good pubs, includes many entries that aren't in the GBG but serve real
ales in very pleasant surroundings. It's listings show what beers are
served. A large number of CAMRA branches have produced guides that cover
specific areas such as counties or regions. Some list all the real ale
pubs in an area others are more selective. A list of these guides which
usually cost well under five pounds can be obtained from CAMRA. Some of
these guides can be found on-line.