By now I have a ton of IDL experience, so feel free to ask me about anything/everything IDL. My top few suggestions:

1. Bookmark the following three pages:
   1. ​http://idlastro.gsfc.nasa.gov/contents.html
   2. ​http://www.dfanning.com/documents/tips.html
   3. ​http://www.fizyka.umk.pl/nrbook/bookcpdf.html
2. There's a usenet group (comp.lang.idl-pvwave) which is incredibly helpful. It has a Google Groups page which gets lots of spam, or you can use a newsreader. I have had many problems solved by the members of this group.
3. Upgrade to IDL 8.0, the new graphics system is fantastic.

--Gray