When I first joined the workforce, blogging was the last thing on my mind. But over the years I have realized that each and every one of us gains expertise at our jobs or on pet projects that doesn't always stay with us. The knowledge we gather in our day to day activities might not seem all that innovative or hard to come by, but as it builds over the years we start wishing that we had kept track what we did in the past.
Blogging allows me to appreciate the value of the challenges I've faced, solutions I've researched, hacks I've invented, plus the pros & cons ... all put down into words that seem like a godsend later on.
Blogging also serves as an excellent resource when you finally decide to move on with your career but quickly find yourself scratching your head as to how to update your resume. This is when you can take a look back at your blogs and remember all the wonderful technologies you've worked with and challenges you've tackled.
Of course there is a huge liability/responsibility that comes with blogging for a working professional which can always be summed up in one sentence: don't ever write about anything that will let your company wring your neck for it!
The basic etiquette that can perhaps keep you safe is simply writing about technologies and challenges in as generic a manner as possible. Focus on the true challenge and nothing else. Of course sometimes if folks in the industry can figure out who you are, who you work for and what you are working on currently then its best to write your piece and delay publishing it online until the information does not leak anything to the competition or is not time-sensitive anymore. And the ultimate "DUH" point is not to write about stuff so smart that it could be considered your companies Intellectual Property ;)
If you start small and cover yourself by not getting too ambitious as to what you write about, you'll gain immense satisfaction by going over the challenges both when you write them and when you review them later. It will give your self-confidence and career a boost as it will allow the online community to get to know how you think and how your abilities may be extremely specialized or widely varied.
So what are you waiting for? Take control of your career and start blogging!