There are a few resources in the web for problem composers. Problem is the usually assume you are already part of the community. As a result one has to wander around to find out what is a grasshopper, a model mate, etc. I already have access to much of this information, but it would be nice to know of a single source (or few in any case) where one can learn the lingo, history, and the kind of questions that modern composers are interested in.
- CHESS PROBLEMS MADE EASY - How to solve, how to compose
- How to compose chess problems and why (You have to register for free to read it)
- Chess Wizardry: The New ABC of Chess Problems
- Compose Like Mozart
- What are chess problems
- For definitions, see Christian Poisson's website Problemesis ("Definitions" menu)
- For an encyclopaedic website, visit Vaclav Kotesovec
- The MatPlus forum is dedicated to problem chess and is frequented by chess problem enthusiasts.
(Edited December 27th: Now I can insert more than 2 links in my answer)
Thanks for the great links above. Here are some more:
Great intro tutorials from a fine composer, Peter Wong.
Incomplete but still very useful multilingual glossary of the keywords underpinning "Die Schwalbe" online database of 350,000+ problems.
Thousands of retro problems with full solutions, and many articles. Minor cavil: there is a little disorganization in article structure following the announcement around 2009 of some technical changes around in castling and e.p. conventions.
A popular forum for fairy chess with very good technical articles by top composers.