Read this article and you'll know more : http://www.webconfs.com/importance-of-backlinks-article-5.php
Reciprocal links have had their day as far as SEO is concerned. But if they bring you traffic, they're worth doing. Reciprocals are now about traffic, not SEO.
For the link itself anchor text is very important. Use the anchor text for the keyword you are optimizing. Also the placement and the text near the link.