Reciprocal links form a vital part of any website promotion effort. You have created great content, or offer a superb product or service -- and now, you want people to know about it.
The Web is only as useful as the sum of its links, as without links it is just a disparate collection of pages. Links are the glue behind the Web. To ensure that your page has the visibility it deserves, you will need other sites to point to yours.
What is a reciprocal link?
Before plunging into the body of the discussion, it is important to define what a reciprocal link is, and perhaps more importantly, what it is not.
A reciprocal link is a text and/or banner link to a site that, somewhere in its pages, carries a similar text/banner link to your own site.
A reciprocal link is a commitment. This link basically says "The site at the other end of this link feels that my site is important enough to link to, and I feel that their site is important enough that I am willing to let visitors leave my site via this link."
A reciprocal link involves an element of trust. Few Webmasters have the time or patience to constantly monitor the sites that link back to them, so you are trusting the other site to maintain the link on their site, and not bury it under other information or delete it during a site upgrade. Trust me, I have experienced both situations, and it can be frustrating when your own links page is in order.
How to present your links
There are many different ways to present reciprocal links. You can clearly designate them as reciprocal links and delegate them to specific areas or pages of your site. You can incorporate links to valuable resources inside your own content. You can choose to separate reciprocal links and other links, or lump them all together.
There is no "right" answer: this depends on the specific site. The important thing to remember is that, no matter what approach you choose, be fair to the sites you are linking to. Do not bury the links somewhere under reams of graphics and text, or attempt to dissuade your visitors from following the links in any way. This includes putting the links inside a single "frame" to effectively keep visitors on your site. If your content is compelling enough, your visitors will certainly be back -- and they will thank you for drawing their attention to other interesting sites.