WordPress is an open-source blogging tool offering an online option that operates a little like Google's Blogger solution, as well as a slightly more complex version that you download and install onto a server. WordPress is incredibly accomplished: the basic package requires next to no knowledge of servers, PHP or MySQL, although it harnesses the power of all three. Moreover, there are lots of plug-ins that allow you to expand the capabilities of your blog further than you would imagine. All of this is free and, more importantly, it's accessible though an interface that's by far the clearest of the options here.