GPAINT is the best PD Art program, it was imported from Germay by Robot PD. It comes complete with its own instructions, however, the screen display is in German but don't let that be a worry as you soon get use to it.
RSXLIB was originally a commercial program, which has now been released into the Public Domain by the owners. This program allows you to quickly and easily build up an RSX command for use in your own programs. You can select the commands you want from a library of sixty existing commands or you can write your own routines and add them to the library. RSX commands add machine code speed routines to Basic programs and allow many extra functions to easily be used.