Hey Matt,
The others said some really good stuff about Wordpress, but I thought it might help to have the options broken down a little more for you.
There's three pieces involved in getting a website. You need a domain. You need hosting. And you need someone to actually design the website for you.
The domain is the actual name people type in the url bar--
www.myawesomedomain.com. That has a small cost.
A website is made up of a bunch of files, just like word documents or images, and they have to be stored somewhere that's accessible to the web. That's where your site is "hosted." This also has a cost, but it's a quite a bit more than domains.
So if you use a Wordpress or Blogger site, they pay for your domain, and they pay for your hosting. So it's free for you, and you have options to create extra pages, pick themes, and modify those themes. They provide basic packages of code so you never have to mess with it. (FYI Google also has similar free websites for anyone with a google account.) It's a great "starter" website.
The other option is to buy your own domain name and pay for your own hosting. This works better for professional sites once you want to be able to have mailing lists, or lots of pages, or hire someone to make your own design, etc etc.
The problem with buying your own domain/hosting is that now someone has to write the code. You can hire a web designer ("small" 5 page websites can cost around $1,000k depending on the company.) Or you can try and do it yourself.
Doing it yourself means either A) Learning how to use a program like Dreamweaver, in which you can design what the site would
look like, and have it generate all the code for you, or B) Learning how to write CSS and HTML yourself. And although the two languages go hand in hand, you still have to learn them both. It took me two Web Design classes to feel like I could competently design a website.
And just to sum it up:
The cheapest, easiest way is to go with Wordpress/Blogger
The next best cheap, easy way is to buy your own domain/hosting and invest in Dreamweaver to help you design the site.
If you want a cheap, professional looking site, do your own domain/hosting, and spend some time really learning how to write CSS & HTML and write the site yourself.
If you want a professional site, and you can afford it, hire a web designer, and then you only have to worry about the domain/hosting.
I'd suggest evaluating where you are in your career, at the moment, and what's really worth your investment at this point. I'd say start with a Wordpress site and then when you start publishing books, bump up to a professional site.
Hope that helps,
-Mandy