You may wonder why I don't especially like frames. There are several reasons, each on its own enough not to use frames. It's also a matter of taste, some web designers just love them. But a lot of websites remove the frames after they have used them for a while. I will tell you why.
Bookmarks and links
You cannot link a framed page properly. If you link the whole page, you will most times get to the home page of the site. You won't get to see the page you're really interested in. If you link the page itself, the layout and links of the page are missing. You will end up with a crippled page.
<!-- frame buster
if (window != window.top)
top.location.href = location.href;
At first sight a framed site may look simple. You don't have to repeat the navigation code, for example. It has its own spot and needs only to be put on one page. This is true for a site with a handfull of pages. But more pages need more navigation bars. When you get to hundreds of pages and dozens of bars, then which belongs to which? It's easy to get lost.
Sometimes you see a page you want to keep, to read it again. So you download the page the subject you want is on. The entire layout is lost. If the information is divided over several frames, you will lose a part. The context is also lost, since there are no links, or at least not all of them, and probably no title.
A fundamental concept in web design is the unit of information. A web page should contain a concise, complete amount of it. With a start, a beginning and an end. A framed setup breaks with this rule. The information is often divided over several pages.
Frames take more time to load than a single page. First the top page is loaded and interpreted. After that the sub pages are called and loaded. You need three or more connections to get the entire page. With bad connections you may end up with a gray area on your page. Apart from that frames themselves take your browser noticably longer to render than a single page.
The seperate loading of pages may cause an unpleasant flashing effect. First the default browser color, then the page background color, then the background image, then the images on the page. Multiplied by the number of frames. Just a matter of taste I guess, but I don't like it.
To be or not to be
Some HTML editors put a style attribute into a frame tag by default. Several browsers don't reckognize this, making your site completely invisible. I've seen (?) a lot of them.
I told you my reservations. It's up to you to make a decision. If you want to use frames, fine. You can make great sites either with or without frames. I wouldn't use them unless I really have to. I'd rather stick to tables. The really important thing however is to make great sites, to get your message across. Not the instrument you use to do that.