I'd suggest
http://thehiddenwiki.org/From there on, you can find a couple search engines on tor, and a couple of linklists.
You can use those to find some forums on tor... and ask whatever links you want on those forums.
Be carefull tough: it seems most sites on there are either illegal, or scams... I personally browsed tor for a while, just out of curiosity, but legit (honest+legal) sites seems to be hard to find.