Web Design in a Nutshell, 3rd Edition

Provide complete noframes content

Framesets should always include a noframes element to provide content if the user cannot or chooses not to view the framed content. It is a good idea to make the complete content from the framed page available in the noframes element and to enclose it in the body element. At the very least, the noframes content should be as descriptive as possible rather than just “you need frames to see this site.”

Adding links to the individual HTML documents, particularly those containing links to the other parts of your site, helps users get to your content without relying on the frameset.