Adventure Probe is perhaps the most well known adventure fanzine. Although not CPC Specific, the magazine does contain a lot of information of interest to CPC users. Readers of Bob Adams 'Dungeon Master' column will probably have already heard of Probe.
Regular features include Software Reviews, Letters, News, Solutions, Hints and Tips. Bugs and Amusing Responses, and Serialised Solutions. Probe also runs the most comprehensive adventure telephone helpline in existence and has solutions/maps for literally hundreds of adventures (available for just a small charge).
If you're an adventure fan then you'll find Probe an essential read every month.