It all depends on what you want to accomplish with your blog. If you just want to write for fun then a free blog is all you need. wordpress.com (not .org) and blogger.com are both good choices.
If you want to monetize your blog through advertising or affiliate sales then you should either go with wordpress.org (you have to pay for hosting and buy a domain name) or blogger.com (not as professional but it gets the job done).
Otherwise you can just post individual articles on hubpages. It's not as friendly when it comes to affiliate links but the ads are built in so you just have to apply to the hubpages ad program and/or google adsense.
There are about a million posts online about how to start a blog. A quick google search or probably even a search on hubpages will bring them up for you.