A few google recommendations (that you may already know, and probably were said, but will expand):
1) on linking, you will never be penalized by having other sites link to you, but your site WILL be penalized if you link to sites that google feels are spam or bad sites. Adding links on forums will count towards your link total, and help your ranking slightly, but google is aware of this. So the only links that really count are links that are on higher ranked pages. Links that are closer to the homepage will also give you better ranking than links that are 20 pages deep from the homepage.
2) Meta tags are basically worthless, google wont optimize for them, but they will penalize you if you put in keywords that are not relevant to the content
3) update, update, update!!! If you don't update your content, your page rank will very quickly go down the tubes. Google thinks people want to view sites with fresh and current content, and if your site does not provide that, then they wont provide the users. My advice is make it easy for you to update your site. Maybe add things which allow the content to randomly change (for example have a pool of photos/text that is changed every day on the website via scripts, that way different stuff is featured on the homepage on different days)
4) don't post duplicate content....if google indexes pages and it sees that text is the exact same as another website, you will be penalized
5) don't forget the text....photos are great, but google is really looking for text content to index
6) my final piece of advice, have your domain registered for at least 5 years in advanced. Google actually looks at how long domain names are paid for, and they figure that if a site has been paid for 10 or 15 years, the owner actually cares about the site and will continue to work on it. Vs domains which are only registered for 1 or 2 years, and usually end up evaporating. This will only slightly increase your page rank, but it helps, and registration is cheap so why not.
p.s. no one actually fully knows google's formula....but these recommendations seem to be pretty safe to help SEO