It should be noted that the term "lane" in the Galloway Hills means a large and often unfordable stream, rather than an easy means of passage. Thus the term "Gala Lane" does not indicate a pleasant path, though the real path may not be any drier, and in fact probably does not exist at all.
The guidebook required is the SMC Lowland Outcrops (2004), and page numbers given relate to this guide.
For the occasional visitor, the SMC Scottish Rock Climbs (2005) selected guide describes a few of the best climbs on the Dungeon of Buchan and has good colour photo topos of two of the buttresses that are only illustrated by black line drawings in Lowland Outcrops.
Maps required are Ordnance Survey Landranger sheets 77, 79 and 83 or, alternatively, OS Explorer maps 318 and 319 which give excellent coverage of the entire range, though unfortunately forestry firebreaks, so often used for access, are not shown.
These pages give a brief description of the main Galloway Crags as well as details of new routes recorded since the last guidebook and a few that have not been previously recorded properly. It does not cover the Galloway Seacliffs or Dumfrieshire Outcrops - however many of these can be found on John Biggar's website, Climbing in Galloway.
As a general rule, routes that are already described in the current SMC guide will not be described here unless they have been poorly described. This means, I'm afraid, that you will have to buy the guidebook: but as all the SMC's guidebook profits are ploughed back into further guidebook production, or given to worthy environmental and access causes, I hope this will not prove too great a burden.