Back in 2007 I started blogging mainly for one selfish reason - to have an online repository of how I've approached things technically to refer back to when required. When I find things interesting, I like to document them for me to expand on later. If a public user wants to expand or contribute to what I’ve posted, then they are welcome to do it.
Blogging soon flourished into something more beneficial and pushed me to better myself in all aspects of web & application development. It had turned me from being a very introverted cowboy-developer to an extrovert with the confidence to push the boundaries in my day to day job just so I could have a reason to blog about it and publicly display what I know.
I highly recommend blogging to anyone, especially in the technical industry. Reading other blogs has shown me that a solution to a problem is always up for interpretation. For example, I may find the solution to one of my issues on another site that I can expand further on my own blog (with references to the original author, of course).
This year, I decided to take things one step further and joined a well known open community called StackOverflow. So far, it's been a great experience and I recently broke the 1000 points barrier. It took a lot of blood, sweat and tears. In some ways, knowing how people rate your answers in a forum can help show you where your skill set is lacking. I'm sure if I look back on some of my earlier posts I've made some shockingly bad suggestions. Thankfully, there are more experienced posters who set you on the right direction.
Blogging and contributing to StackOverflow can also have an unexpected impact - employment. The web development industry is very competitive and it's up to you to set yourself apart from the rest. Potential employers can have a great insight to what you're capable of and demonstrates you can communicate your technical knowledge.
If I known this earlier in my career, I'm sure things would've been different and would have had the opportunity to find a job in web development sooner. So start early even if you're studying at college or university. When the time comes to getting a job, you can truly show your potential!