New with a couple of questions

Hi everyone,

I've just discovered this forum and so far, it's been really helpful - thank you all.

Okay, well I'm primarily a photographer. A friend of mine started a site - 'Nombrilla's Belly Buttons' in 1999 and I took the (better quality) photos for her. Sadly, she died in November 2006, but asked me to continue the site for her.
I know next to nothing about being the webmaster for an adult-orientated site. The site ranks pretty well in search engines, but as it's a really small niche market, with no more than 30 active members, how should I promote it? At the moment, it pays for itself (just) but with no real profit.
I want to continue with Joanne's ethic for the site (light soft porn, concentrating on belly buttons) and plenty of sites link back to us. It was the first 'belly button fetish' site to have a forum and is the longest running on the internet.
Are there certain things I should look at doing?
How should I approach finding new models?
Joanne added links to similar sites, but wasn't into advertising banners
Would people be interested in swapping 'linked' galleries?
We currently use CCBill (expensive, but reliable) but can't afford the $750 sign up for Visa and we are hosted by Lunarpages (great cheap webhost) though a friend has offered free server space

Any hints or suggestions would be very welcome and thanks to all of you in advance.

Very best wishes,

Christy