I wouldn't delete this, as it's not an advert, and even if it was, I personally dn't have a problem with members plugging their own sites, so long as they're loyal members and they don't take the piss with it. I'm sure Bav and Satty are the same.
As far as starting a new site goes...It's easier said than done unless you're prepared to pay for the lease of the Forum software, or pay to buy it, either way, it can be costly. You'd need a name that search engines would pick up on, and the only way you'll be able to do this would be to pay for the domain. You'll notice that free forums have a long name which includes the host name in it, such as car-forums.proboards23.com or similar. This won't get you any new members, just ones that you invite yourself. Either way, it's not necessarily an easy job keeping members interested, because as you know, some just join and forget about the place etc!
The best way to do it would be to pay for the hosting, plus invite a fair few members from other forums that you're at and are confident will help the place out. That way, you should have at least 20 or 30 regulars to start up with, and this will look good for new joiners if they are posting already! As far as Mods go, you don't necessarily need any to start with,as too many could make the place look like it's got more staff than punters, it ya get what I mean!
What ever you decide, good luck with it!