Well, UGN was already established when I purchased it, I purchased it from BlackBeard in 2001 for $3000 and yeh it can be hard.
I reccommend that you have a strong knowledge of PHP/MySQL and Perl (if you use a perl bulletin board like we do) before you begin.
For bulletin boards I reccommend UBB.Classic (what we use, Perl/Flat files) or UBB.Threads (A PHP/MySQL version of our board). Both of these are non-free BBS' that are available from
http://www.infopop.com which are the only two BBS' that I reccommend using.
Mainly you need to make your own content (images, designs) and find some good content (text files, zines, programs).
If you want a pre-made setup I reccommend using a Content Management System like PostNuke which can be found at
http://www.postnuke.com/ and you need a webhost that's understanding (we use
http://www.hostnuke.com/ who I help run).
Best way to keep people off your back, don't condone illegal activities, granted hacking is illegal, but computer security isn't. It's all about how you lay out your site...
Any other questions I'll be happy to answer...