Creating a blog may seem like a lot of trouble but in all reality it can be very easy. First thing is pick a topic for your blog. I say keep it very simple, a blog is really like an online journal in which you can create a daily post or a monthly post the choice is really yours.
Choosing a platform where to place your blog would be your next step. For me I tend to use blogger.com because the tools are easy to use plus it's free! I first think about what am I going to talk about in this blog. Than I ask myself this question? Do I know a lot about the topic that I picked? If so I say roll with it if not get brainstorming on topic ideas until you choose one that you feel you could write a lot about.
Next keep sure that you place no type of links within this blog for at least 1 month. You want Google's bots to crawl this blog and from what I have read you will receive a better ranking if you choose to wait to put you own self serving links. Now with that in mind I am no guru that is only what I have learned from my own reasearch when making a money making blog.
Feel free to add Google Adsense to the blog but just wait to add your own links that way you have a better chance of reaching high in the search engines.
Now once you have picked your blog topic now you need to decide how often you will post. I say once a day is better but a few times a week is ok as well. After you create a post be sure to promote the blog in someway online, someways to promote for free would be a social network or via email to a few friends you talk to you.
Also make sure that you add some keywords or tags after every post as well. You will also have a better chance of being found in the search if you add tages to each post. Make the tags make sense with the content don't just use highpaying words to think you will reach the top that way.
In closing the best way to start a blog is this way from my opinion and as you go you can learn more and more along the way.