I strongly recommend WordPress. Personally I'd recommend getting it with a hosting plan just to give you some additional control (see wordpress.org) but if you want something a bit more simple to use have a look at wordpress.com.
WordPress.com is the same, just your site will be hosted by them and you'll have less control. On the plus however, you're far less likely to encounter issues, and unless you need a domain name it'll be free.
WordPress.org gives you the script which you can install on a hosting plan with someone else. This does require a bit more effort to get up and running, but most hosts have some way to install it automatically, and if they don't, I'd be surprised if they wouldn't be willing to install it for you. It's a more costly option, but if you want to have more themes, for example, than Wordpress.com offers or more plugins or another feature that wouldn't otherwise be available, it's a pretty good option.
I wish you the best of luck.