Here are the tools that you can use for free. If you want you can register for a free account and then you can save your work, so you can allways come back and check stats of your web sites, domains, keywords and etc...

Free SEO Tools That Will Help You Rank Higher in Search Engines

The first step to increasing your website’s traffic and search engine visibility is picking the right keywords and keyword phrases to focus on. If you don’t choose keywords that are frequently searched, people will not be able to find your website through search engines like Google, Bing, and Yahoo! – no matter how great your site is otherwise. But if you choose the wrong keywords, people won’t be interested in the content you have to offer and you’ll have wasted valuable time and effort in producing that content.