You will probably find a lot of the most useful information on this forum! You'll see that the second most popular TAG on the forum (after Clarity) is "GEL" so there a lot of threads on here - have a search around! For example, attached to this thread;
2297925 are a couple of useful howto documents and examples. The "real" documentation is that provided by CA in the "Integration Guide" (downloadable from casupport if you don't have it) and the internet "jelly" documentation at
http://commons.apache.org/jelly/overview.html -but you have to understand the concepts to get the best out of these (since they don't explain "why" you are using GEL, only "how"!) Post questions on this forum and someone will usually chip in with some help! David MortonCapgemini