A decently reliable/reputable web host usually costs about $9-10/month. So I don't think you're going to get a much lower monthly rate than danlefree's suggested HostGator plan.
Though I'd recommend just getting a standard $8.95 DreamHost account. You get unlimited nearly everything (domains, subdomains, MySQL databases, shell accounts, ftps, bandwidth, storage, etc.), and you get a free domain for the life of your account. A lot of web designers have single-page websites but still get this type of standard shared hosting account. It's only $4/month more and it gives you room to expand.
Also, be aware that, even though GoDaddy and HostGator offer super-economy hosting plans with slightly lower monthly rates, you could end up spending much more with them. For instance, if you need an SSL certificate, DreamHost sells them for $15/year. But GoDaddy charges $50/year and HostGator charges $150/year. DreamHost also offers free private domain registration, whereas GoDaddy and HostGator both charge $10 per domain extra for it.
Personally, I'd choose DreamHost just because they have higher standards of ethics than many of these others companies. (They don't work with domain squatters; they don't try to nickle-and-dime you; and they don't use your expired domains as their personal billboards).
Also, because DreamHost's basic hosting plans comes with pretty much unlimited everything and lets you create separate users for different domains, you could just share a hosting plan with a few friends or other local businesses. If you can find 4 other businesses that want cheap web hosting, you could each pay less than $2/month and still get a far better hosting plan than what you'd pay even $10-15/month for elsewhere.