in short getting backlinks from your own network sites or blog for getting deep study pls use google.
this is what I do. example: 1 main domain 1 dummy blog 5 other blog dummy blog and other blog should be the same niche with main I wrote article or buy review post at 5 other blog, each post got 3 links: 1 link to main domain, 2 link to dummy blog at dummy blog ofcourse got link to main site. it;s just small example, but it works for me, I buy 5 review/2weeks-1month, 5 blogroll/1month, cost money but worth it, still profit. if you put site on squidoo, etc like above actually it's not linkwheel, thats good backlink, cos it's not link to each other, only to your main site.
Link Wheel: It is a wheel like structure with web2.0 sites(wikispace, weebly, hubpages, etc) which are interlinked each other and points towards the site which you promote. Link pyramid: It is a three layered structure of your links such as base links, mid-grade links, highest quality links. Base links are bottom layer of your pyramid and are low quality links. Then next level of links are mid-grade links. These links are from authority sites. Then Next level of links are highest quality links. You can even rank well with base links and mid-grade links. This is important because it brings as natural link in the eye of Google.
Linkwheel is good stuff for improving to keyword ranking and traffic, online07 has elaborated nice picture here.
I follow a tree structure with no closed loops (no-interconnection). Mainsite > subsite1 and subsite2 subsite1 > subsite1.1 and subsite1.2 subsite2 > subsite2.1 and subsite2.2 and so on. Works fine for me.
A link wheel is a way to gain authority and exposure to your “money siteâ€. Link wheels are pretty simple in princicple as they consist of several Web 2.0 properties which link to both your money site and each other, creating a loop of sorts. The Idea behind the Link Pyramid is that while link juice can pass from one site to the next, ranking penalties generally stop after one hop. It works on the premise that the lowest quality sites link upwards to the next higher quality sites in your network. Sites can link laterally and upwards but not downwards.