http://www.portforward.com/routers.htm

The instructions over there are pretty good.

I don't think the new owners of BearShare are taking requests anymore. They
have been ignoring the users since they "bought" it virtually at gunpoint from
Free Peers in the spring of 2005.

If you're using BearShare 5.2 or 6 you should go to this thread and get 5.1
too. The newer versions don't even come close to it's performance and now
they don't let you download whatever you want anymore.