Russell provided some solid advice already, but to add, lots of gangs use forum software hosting as the basis of their online presence.
Back in the day, I used
http://www.freeforums.org/ - they provide free hosting based on the open-source phpBB platform.
Alternatively, another good option is IcyBoards:
http://icyboards.com/ - they use MyBB - the same software that we use!
To further educate yourself, look through a couple gang websites (there's plenty in our Gangs forum) and scroll to the very bottom of the page - there will usually be an indicator of the platform they're using.
With that said, don't hesitate in being creative - play around a bit, see what (and what does not) works for your needs.
Before my time at LVP, I owned several forums and was heavily involved in some pretty large and diverse communities. One thing I learnt: MAINTAIN BACKUPS!
Dont let your work go down the drain, and it's never over until the fat lady sings - keep at it, you'll be surprised what you can learn.
Good luck!