before moving to pure ecommerce/digital marketing this year, I worked in digital news publishing for 15 years previously. During that time I was exposed to: Drupal, WordPress, home grown Cold Fusion CMS I built in the 90's (may it rest in piece), Ning, Tumblr, TownNEWS Bloxx CMS, the very expensive platform Clickability and Blogger.
I am in agreement with Ryan that WordPress is probably the simplest and easiest to get up and running quickly. Just set this up in 2 weeks: http://community.steripen.com
If all you need is to post content: text, images & video with some social media push capabilities, then you can be in business very quickly.
I loved Drupal but had a very difficult time getting it implemented live as customizations were time consuming/complicated (for me anyways) and outsourcing quality Drupal help was expensive. It's great for community building but might be overkill for blogging. Acquia has some great use-case builds that you might find useful to check out if you need more than basic blogging. Basically from a programming perspective it was over my head. That is just as much my limitation as the product. I also didn't find the blogging tools to be very robust. As I recall it required a lot of plugins to do some of the most basic things that wordpress does out of the box.
Three years ago I walked into a job where there were 5 Joomla installs pumping content for 1 newspaper in Utah. It was a nightmare for me. Joomla seemed like a big step backwards. to some degree though, these products have unique feature sets that are geared towards certain product dev groups so this is a very opinionated discussion for sure. By the time I left we had moved off Joomla to something called TownNews Bloxx CMS which is overkill for you.
As I recently learned, be careful about setting up a new blog. All best practices here at SeoMoZ point to keeping your blog in a subfolder of your main site. Due to limitations of my cms, I wasn't able to do that short term.