I'd like to learn Emacs, and was wondering if anyone had any good resources (free or otherwise) to recommend. I'm mostly interested in programming Emacs, starting from the basics, and lots of "exercises". I have used Emacs and most of its editing features, although I'm a bit rusty so a very quick refresher on that would be useful as well.
Thanks
Edit: Thanks for the suggestions. I'll have a look and update with what I liked...
Emacs itself includes a tutorial with exercises that guides you through the basic features and editing commands. You can find it in the Menu under 'Help' or by pressing C-h t (i.e. press Control and 'h' together and then 't' alone).
One thing to bear in mind is that all emacs configuration is programming.
PlanetEmacsen is a good RSS feed with lots of tips.
Xah Lee although he is apparently considered a bad troll, has some great emacs programming stuff.
Also whenever there's a function or keyboard shortcut you're not sure of, try C-h f and C-h k respectively, then follow the link to the source code for that command.
For exercises, Lair of the DustBunny did a very long series on rewriting python mode from scratch.
You could also try writing the PLEAC elisp section. That's a very good way to compare elisp to your favourite language.
Last week I purchased this Peepcode screencast and really liked it. It walks you through the basic features (editing, loading saving, buffers) but also dives into some advances topics, like programming emacs lisp: