There are some few things that you need to know before you start earning. Some of those basic requirements are:
1. Know how to edit HTML. Know at least how to add links.
2. Know these terms like Link, backlink, Pagerank(PR), anchor text, webmaster forums, web-directory, domain name, web hosting etc. You can check them up in wikipedia.org
3. Join webmaster forums like Digitalpoint and v7n.
4. Have a free blog from blogger.com as a testing blog and start posting.
If you have done the above few things, you are near towards the earning process.
The next thing you should do will be seen in the next post.