I think that having a blog is a great learning tool. It really helps you pull together your thoughts and ideas on a particular topic. Once your blog has an audience, you then start to learn from your audience. I personally get very little feedback on this blog, but yet it has really helped me understand a lot about engaging in a conversation that is distributed over the Internet.
If you are interested in improving your knowledge and understanding on any topic, start a blog and start writing about that topic. Where to start? Try Blogger.
The other great benefit is being able to go back and look at your ideas and thoughts at that time. I just went back through and cleaned up some of my posts from the last three years. It was great to see all the topics and ideas that I was interested in during that time.