When looking for websites to add links from them to you, there are some things you will need to do to check their validity.
The first is to make sure that the site is not a link farm. Here is what Wikipedia terms a link farm
‘The definition for link farm, as described by Wikipedia, is a collection of websites which contain hyperlinks to boost page ranking of targeted sites in search engines. The hyperlinks are usually created by computers, rather than human beings.’
One of the best things you can do is check that the site is actually listed on google and has not been banned.
Just do the following search site:www.thesiteyouwantotest.com/thepage.html. If the site is indexed and has not been banned, you will see some results.
The second this is to make sure that the links are not added as no follow links. Just open the page source and search for rel=”no follow”. If that is found, it’s not worth the link, as the site is telling Google not to bother with the link!