Wordtracker posted an interesting article about evaluating sites for link building.
Link Building is the process of getting links to your page to improving your rankings in search engines. It is quite important for SEO these days.
Factors discussed in the article include relevancy to your own site, fresh content, current link numbers, and standing on search engines such as Google and Alexa.
What I consider the easiest way to do a link building campaign is using Link Assistant. It has a lot of tools for finding the best link sources for your relevant keywords, and can show several of these factors for you. It also manages your link pages for reciprocal link exchanges, as well as checking if links pointing to you still work – including generating and uploading your link page.
Well worth checking out.
Wordtracker has their own tool for this, but Link Assistant beats it on price by quite a bit.