Here is a little guide I wrote up here: http://www.110mb.com/forum/high-ranking-spot-on-google-using-specific-keywords-t45214.0.html
Getting a good google ranking is much easier than it seems. If you are in a small enough genre you can be in the top 10 within just a few days as long as you play your cards right (and work hard :D ).
To explain how to advertise correctly on a forum, here are a few tips.
First: The format of the link
Code:
[url=http://yoursite.com/ ]The Text You Want Google To Rank[/url]
* Make sure to remove the space between the / and the ] in "[url=http://yoursite.com/ ]"
An example would be:
Code:
[url=http://rat-info.com/ ]Rat Info[/url]
The text will display as Rat Info, but still link to the site. This is called Anchor Text
When google indexes the link it remembers what the text was and compares it to your header. This way your site is indexed correctly. Anchor text, meta descriptions, and keywords on the page work together to help your site rank higher on google. You do not need a high pagerank to get a high google ranking (though it helps).
Second: Image Links:
Image links are good for drawing members directly, text links are better for drawing search engine rankings. I would use text links and image links together in your signatures to maximize your exposure. I suggest you put your text links first though as search engine spiders may follow them as it scrolls down the page and as I mentioned, the text links are more valuable to google than the images.
Third: Keep linking!
Link your site as often as possible. If you are ever making reference to your site, then please link it as well (using anchor text).
With these tips hopefully the reader will be able to increase their own forums google ranking.