A link wheel consists of separate URLs with content on them and two links within that content. One of the links points to the site you are trying to rank, and the other link will point to another URL in the wheel. This other URL in the wheel will also have content on it that contains two links, one to your main site, or “money site” and the other to yet another URL in the wheel. Thus creating a virtual wheel with your main site in the middle and other URLs around it that all link to each other and your site as well.
Download the PDF:Link Wheel – TDWS
‘legitimate’ link wheels
TechMediaNet have been buying up massive news/media sites which arent really monetised (adsense) like http://www.space.com/ http://www.ouramazingplanet.com/ livescience.com and others and generating, admittedly good quality, curated content.
Then seeding them with content with backlinks to their money site, toptenreviews.com which in essence is a review site with thousands of pages loaded with affiliate links no better than any of the other site out there. e.g. http://www.livescience.com/9755-bing.html