Without proper optimization, most of websites will remain undetected by search engines. A proper Search Engine Optimization will help you to build, format and host your web site in such a way that the search engine spiders can easily understand index your site in the search results. Here are some useful SEO tools that can help you in this task for free and at a nominal cost.
10 Free and functional SEO tools
Some Wonderful SEO Packs Available for a Nominal Fee