I've been designing websites for 6 years now, and the way I see it you have 3 main options:
#1. See if your current blog service offers any upgrade packages that would allow you to purchase your own .com domain name and fully customize your page layout while still maintaining your current blog.
This would be the best option because it's cheaper than hiring a professional and easier than designing the site yourself. This is also more convenient for you for several reasons: First, you keep using the interface you're already comfortable with. Second, most blog services will change your old URL to redirect to your new URL for at least a few months. This is more of a convenience for your readers than for you. Third, all of your old posts are already archived. If you design a new site and stop using your current blog service, you'll have to re-archive everything yourself, which will probably mean hours of copying and pasting. Or worse, depending on the Terms of Service you accepted when you signed up for the blog, you may not even be allowed to re-post your blog posts on another site.
#2. Hire a professional to design your site.
This is the most expensive option, but if you have no prior experience with web design then this is the second-best option next to upgrading your current blog service. If you hire a professional company, you'll get full customization, full technical support (don't pay anyone who doesn't offer this), an administrator page with an interface for all the features you want, support for a membership service so members can sign in, post comments, vote on polls etc., and they may even archive your old posts from your original blog for you. Bottom line, if you hire professionals they will give you a great-looking site and make it easy for you to maintain it, but it will cost you. If money is no object then I guess this is technically your best option instead of #1... but I'm guessing if money was no object you probably would've gone this route in the first place instead of coming here to ask for advice.
#3. Design the site yourself.
This is probably the cheapest option because all you're paying for is the domain name and hosting space, however if you have no prior web designing experience then you'll find this to be very difficult. Programs like Dreamweaver will go a long way in helping you to design the layout of the site without any knowledge of markup or scripting languages, but when it comes to setting up member accounts and making forms and polls that actually do things, and (most importantly) making all of these input forms SECURE and hacker-proof, there's no easy way to do that without having a good understanding of web design, particularly server-side scripting languages like ASP or PHP, and knowing how to use Structured Query Language to set up databases for storing member data and things like that.
Basically what I'm saying is that drag-and-drop design programs like Dreamweaver make it really easy for people to design great looking STATIC websites with little or no web design experience, but if you want all the features you'd expect from a normal blog then don't expect to be able to learn that kind of stuff on the fly. That being said, if you want to learn about web design (not drag-and-drop web design, but writing code from scratch in a simple text editor), this is the best free site on the web:
W3 Schools
I started getting into web design when I was 15 years old and this site taught me more than I ever learned in high school or college courses.
