I am creating a website for my small business and I'm not very web savvy. So I got a basic monthly package through Yahoo Small Business, and frankly their web design package isn't that good. I've found another company I like better, and they told me I should "point" my registered domain name to them for hosting. How do I do this? And if I do, will I end up paying both Yahoo and the new company a monthly fee? I would appreciate answers from anyone who is experienced with this.

You have to change the DNS servers to point to the new host and they should propagate within 24-48 hours.

You terminate the hosting with Yahoo and go with the new host. I've done this with a few of my sites, so this is pretty easy stuff to do. Sometimes the host will do it for you, mine did at least.

If the new company is going to be hosting your website and domain name, then no, you will only need to pay the new company. The process of moving your domain varies between hosting companies. If they are a decent company they should offer you some free support.

If you need help designing a website, check craigslist.com in your local area, and then look at computer services. many local web designers offer website desgin for under $500, and they will deal with the setup usually.