How To Put A Forum On My Site, VBulletin? PHPBB?

Im trying to put a forum onto my website but I am so stuck as to where to start.

I have got the site up and running and I have looked at PHPBB and VBulletin3.

I have seen it saying things like you need a MySQL server and a database.

1) I have a computer I could use as a server if necessary
2) I havn't touched a database in about 5 years!!!!

Im basically looking for someone thats setup a forum on their site before to show me step-by-step the process as Im a complete newbie in that area!!

I have got Windows XP - VBulletin - 3 Sites (1 Needs Forum) - All Sites With PHP Support.

I have seen sites where you can have a free forum but I think I would prefer a more professional looking site with a built in forum rather than having to link outside of my site.

Any help would be greatly appretiated