While you are placing or suppose to making back links for your website,you should be enough qualified to judge the linking page quality.Their is a huge clause and references are available on the web to make perfect links for your website and give you the best results to bring you most targeted traffic as well pass the link juice.
But while you are placing your links or making your links their is some specific guidelines but among them personally I like few out of them,today I am sharing those :
1.Google PageRank: PageRank is main criteria while you are making links for Google ranking. More PageRank links,more value for your website.Install Google tool bar to measure the PageRank.While you place your links or Pr1 out 10 scoring point, then this link will carry a link juice,traffic and PageRank which is backbone of Google algorithm even for Latest Panda Algorithm.
2.Relevancy:While you are placing the links you should be careful enough that linking page is almost relevant to your industry.Relevancy is one of the major part on Google guidelines.
3.Link Trust:The linking page should have enough trust on web, that page should have decent no of trust worthy inbound links to establish himself a trust worthy page.
4.Domain Authority: Domain authority is another big factor from my point of view, which absolutely depends on the Domain age,domain name,domain consistency,Pagerank,In bound links,quality content.Try to avoid those links which dont have enough domain authority and made for only link selling purpose.
5.Out Bound Links:Always choose less no. of OBL pages, the reason is more PageRank juice and traffic resource.
6.Cache: Check how often the linking page is cached by the Google bot, which is significant criteria for good links,more frequent cache, is positive sign from Google.
7.Alexa Rank:If you are focused on targeted traffic on your same industry from the linking website, then you should check the Alexa stat,how close rank its holding, that will give you traffic estimation of linking page.Install Alexa tool bar to your browser for quick view(Alexa rank based on there own crawling/parameters,as a free tool its good)
8.Content:Another vital issues for latest Panda algorithm is while you are placing the links, check the link page having any dupe content or not,if it cross the risk level then ignore it to avoid unnecessary penalty.Use copyscape.com to check the duplicate content issues.
Here are the few basic points I use to follow generally, and in between you can use some tools to justify the linking page quality I use seomoz link scape and majestic SEO,personally I liked their metrics, specially mozRank and MozTrust is valuable to jsutify link quality.Some points from Google about Link schemes:http://www.google.com/support/webmasters/bin/answer.py?answer=66356