Avoid the following things which can get you in trouble with search engines:
- Don't use hidden text or hidden links.
- Don't employ cloaking or lightning fast java redirects.
- Don't load up your pages with irrelevant words.
- Don't create multiple pages, sub-domains, or domains with substantially duplicate content.
Did you know that every page of your website stands on its own?
Every page should have a unique title, description, and keyword tag. The description tag should describe ONLY that page. The keyword tag should include keywords for just that page. Include 5-6 keywords, including the main keyword phrase and synonyms of that keyword phrase.
Don't make the mistake of including every keyword that could possibly describe what your site is about in your keyword tag. Make your keyword meta tag specific for each page.
The keyword tag holds very little importance anyway, but be sure to make it page specific.