Tracking down the right GPS. There is a good basic guide on Amazon.com entitled Tracking Down the Right GPS. It covers hand-held units and also units for driving and boating. Useful reading, although once decided you may be better buying from amazon.co.uk.

A Practical Guide to GPS by Don Bartlett is a very comprehensive guide to everything you want to know (and everything you may never need to know as well) to GPS. If all you want is to buy a GPS for geocaching then this guide is probably too detailed to be of use but if you are interested in the possibilities, read Don Bartlett's Guide and you will know more than enough.

gps information.net is full of reviews about indovidual GPS units plus an enormous amount of information on almost every aspect of using and enjoying a GPS unit. It has links to information on maps, software, FAQs (Frequently Asked Questions) and much more. Probably the most comprehensive site available, you can find it at gpsinformation.net

A GPS User Manual for Garmin users is an excellent guide to everything you can do with a GPS. Specifically written for Garmin users, the guide is nevertheless of interest for anyone who wants to get the most out of their GPS unit. Written by Dale DePriest, the guide is available free on his web site.