The damn thing still hasn't arrived, so maybe it will be obvious.

Anyway...

If I want to compile something, say slrn, can I cross compile on my linux box and install the result, or do I need to compile on the n800, and if so do I need to add programming repositories?

(and do I need to build myself a Debian box, as I run Fedora?)

is there a software/compiling howto anywhere, or is it a matter of combing through forum posts?

Is there a master list of repositories anywhere?

is there a list of what libraries are available? What languages?

Zebee

Setup scratchbox as per the instructions on the maemo.org site

Also the "developpers" subforum contains some entries. Do the mentionned setup in the howto. If you are stuck, ask support in this subforum. It is surprisingly easy to develop for these beasts.