That is a cool story Lisa. So many people opt for the "how to make money online" blogs and I think that's one of the worse topics you can get into unless you have a unique spin/approach to your site. Unfortunately most people don't. Plus, the golden rule is if you aren't making any money, it's a bad idea to build a site telling others how.
I also agree a blog is a great place to get your feet wet. Just understand a Web site allows you the flexibility to do so much more so as Lisa said, you should plan on expanding to a Web site eventually.
A lot of people go to
www.namecheap.com for domain names. GoDaddy.com and WebsitePalace.com offer superb, cheap hosting at about $3/month. So you can't beat those prices. So running a web site is extremely inexpensive these days.
So I ask you Emily, what do you like? Is there a topic out there that interests you? A hobby? sport? Topic of interest that you could ramble about for days? The more specific you can get the better.
That Prison Break blog is a great example. It's not an extremely saturated topic and it's very specific so his audience. He could branch out and do blogs/sites on other related shows if he wants or build a site that will allow him to do more interactive stuff like chat rooms, message boards, etc. But he's starting small with a blog and now he's got a small following that he can use to leverage another site or blog down the road.
And 400-800 visits a day for a blog that's only two months old is phenominal!
Do you have specific questions on how sites can make money? As Lisa mentioned, Google ads is one common way. Affiliate programs are another. That's when you join forces with an online company and they provide you with the links to promote their products on your site or blog. You get paid when people buy anything as a result of a link from your site.
So for that Prison Break blog, that guy could refer his audience to the DVD set from Amazon.com and Amazon would pay him for any sales he makes. Most affiliate programs are free to join. You just go to the site, apply and instantly you're ready to put your links up on your site.
This all takes time so understand it's not going to happen overnight. Take your time on deciding your topic. Realize that traffic is going to be your biggest challenge so it's important you understand what it takes to get ranked high in Google, Yahoo, Live (MSN), etc. SelfPromotion.com is a great site we usually recommend here 'cause it shows you how to build traffic to your site.
Another important point... There is no such thing as "build and they will come". You do have to learn a bit about marketing and part of that starts with identifying the type of audience you are going to focus or target. Then research where these folks hang out.
For example if you are doing a site on baby tips, ivillage.com is a common place for moms. You could join their forums and promote your site in your sig file. Again, marketing is everything out here because no matter what topic you choose traffic is everything.
Just take it one step at time. First, choose your topic and then go from there. Good luck!