The concept of links marketing is fantastic. As humans, website must have friends and good friends who are related to each others. If your website is relating to bad website, your website will be regarded also bad by search engines. If your website is relating to websites with high reputation, your website will be also be valued.
Good website to link must have the following attributes
- Website not penalized by search engines
- Website of either the same nature or have at least webpage of the same nature