I've been meaning to work on some documentation for Pligg. I've been waiting for the next major release though which isn't far off. The ultimate way to get help is through the IRC room. There's usually someone on during the weekdays from 10-6pm EST.
IRC:
server: freenode.net
channel: #pligg
if you have IRC software intalled try
this link.
If you don't have IRC software, if you use Firefox you can try the Firefox extension
Chatzilla. If you have a PC you can download and install
mIRC. If you use a Macintosh, try
Colloquy.