It’s easy to get started with AdSense and it only takes a few minutes. You fill out one single online application and that’s it. Once you're approved, it takes only minutes to set up AdSense; all you have to do is copy and paste a designated block of HTML into the source code for your site. Once you do that, targeted ads will start showing up on your website.
In order to create your adsense account, go to www.google.com/adsense and sign up there, but first you must have space on the web where you will be able to post your ads. The easiest way to create a blog or a website is to join Blogger.com. It is free and easy to maintain your blogs and post ads on it. So what i suggest is to open an account in Blogger first and from there you can start your Adsense account.