Id start by changing your meta title on your homepage to something more relevant to your keyword requirement. Existing <title>Chattennis.com</title> New ! < title>Tennis Forum | Improve Your Game</title> Just a thought Good luck with the site
The advice of WPOSolutions should definitely be heeded. The title tag is crucial. If u want to dominate the tennis theme u should also consider writing articles for your site. Maybe a general site about tennis with all the related topics together with your forum could be an idea. Much work to do, but thats what google is looking for. Furthermore, write articles on article directories to enhance your linkpopularity.
You can add a small introduction about the site which should give an idea of what the site is about. This content needs to be added especially for the search engines, and you can target 2 - 3 of your main keywords to it. It will also be useful for visitors, but since most of them would already know what the forum is about, it wont be too useful for them. You should still add it for the Search Engines. Something like this:
I agree about the title tag - thats the most important - you could also add some more to your description tag <meta name="description" content="Tennis forums designed to help you improve your game."> I recommend using up to 150 characters
Hi, Please do let me know if you need any help with SEO, I can get your website on first page of google on keywords of your choice. cheers Angel rabbits