Can an iframe be placed in a web page, and if so, are there guidelines to follow?

Yes, there are no inherent issues with using iframes. The iframe content will be read as part of the page that contains it. If the iframe presents a distinct block of content, such as an advertisement or a video player, then you can give the <iframe> element a title attribute value that describes the content.

More details are available at: http://webaim.org/techniques/frames/#iframe