In reply to sethmford:
SMC District Guide to the Cairngorms has excellent suggestions for ski touring routes in it. also lots of wider information about the area, hillwalking, history, flora/ fauna. some rock & ice info, but a bit dated now. But really, it's worth buying if only for the ski touring sections. Particularly as the SMC ski touring book is out of print.
http://www.smc.org.uk/publications/?ID=8