You should do a search on "search engine optimization", generally the rules apply across the board, important things to consider are keyword density and frequency, too little=low page rank, too high=spam and is not trusted by the search engine spiders. Also back links to the main domain and length of registration of the domain itself are a consideration. Not sure how important metadata tags are anymore, maybe someone else can shed some light on that. BTW there are folks out there that specialize and make a living in this exact field. Check out GFY dot com .
Almost forgot, make sure to submit your domain to search engines so they know you are out there.
Paully