Finding geological exposures can be tricky for the amateur, making sense of them even more so. This excellent little book largely solves that not just by having excursions with the grid references for the exposures (using a gps or smartphone it's possible to locate them fairly accurately) but complements this with first rate pictures and descriptions, which gives confidence that you've found the right thing!
The excursions assume a good level of fitness, more because of the roughness of the terrain than the actual distance. There are only a few tracks on Rum and the exposures are not exactly handy in many cases.
The descriptions of the exposures, and general introduction to the geology of Rum are clear and well-presented and suitable for the enthusiastic amateur, but the challenge of finding the sites and the the interesting types and patterns in the rock should also appeal to everyone who is fit enough to enjoy a day out in the wilds.