According to the Organic SEO the sites which are good for linking are :
- The linked site should have quality Content
- High PR site would be more valuable for linking
- Old sites are also good for linking as they are more reliable for long term partnership in comparison of new ones.
- The linked site must be to your theme related
- .org, .edu sites gives more benefit than other domain sites
- Try to get link from Home page
- The linked site must be indexed by Google and should have some backlinks
- Your link on other site should not be broken
- The page having less links on it would be better to link
- Include your targeted Keyword in your link and could include paragraph which will help your site to describe itself on Google
