If you want to start your own blog, and begin finding readers, earning some small money from selling ads, and expressing your ideas here is one simple way (the way i started) to do it.
1. Pick a topic
Make notes. A list of blog topic ideas. Pick a topic that interests you, that you have insight into, that you have access to pictures or inside information. A topic that you enjoy searching or already have good resources for is key, otherwise you spend all day trying to find out what to write about. I chose art, since I'm an artist, health & immortality, since I want to live forever, and blogging, since i keep diligent notes of my blog progress and think it could help others.
2. Blog Host
Go to www.blogger.com and sign up for a blog account. There are a million other blog sites that you can use. Too many to even list here, simply google search 'blog' and you will be flooded with blog hosting sites. A really serious blogger will host his own blog, and pay to have a site designed with an intricate comment & login system, which unless you are a computer programmer is a little on the spendy and time consuming side.
3. Google Adsense
On this blog, I actually use Adbrite, which is a google adsense competitor. I do this to test out the product, and run adsense on my other two blogs. You can choose either, see my post Adbrite Vs Adsense to see the ongoing advertising battle. I always suggest adsense to newer bloggers because its very simple and easy to follow, but I would not deter anyone from giving Adbrite a shot right out of the gates.
4. Spread the Word
Craigslist.com, Myspace.com, reddit.com, digg.com, stumbleupon, ect. Sites like these are prime areas to find readership. Hit these sites, sign up, post your posts, get readers to check out your work. I strongly suggest finding forums about your blog topic, joining and getting involved in the boards. Lead interested people to your blog. Also use sites like blogrush & blog catalog to find other readers and boost hits. Then research pinging, and ping your blogs often. Once a week to be sure your posts find their way onto search engines.
Consistency is the key here. It takes a lot of work to get the ball rolling. Figure out how often you have time to blog. Try to keep a schedule, a pattern, and make sure you are making quality posts.
See my 30 day blog totals here