Reciprocal links have mixed reviews; one-way back links are great of course, coming from a respected 
site, but there are times trading a link with a site in the same category as your own is fine. As long is it isn’t the only type of link you have.
You will get emails from time to time from someone you do not know, asking for a link in exchage for theirs. The first thing you need to do is check their site and see who they are. Scroll to the bottom of the page and see if there is a web designer listed. Check the “about”, “contact” and legal pages.
Check their Alexa rank. Other good resources are Quantcast and TagUrls.
Okay, you have done your homework and the site is legit. You still may want to check one more thing. Try this free tool that tells you what sites are linking back to you. If your new associate is not on the list, they may have placed a “no-follow” tag, hopefully inadvertently. The search engines actually will still follow the link to your page but you will not get rank benefits.
Here is the link to check your inbound links: ValidRank
If this happened to me I would definitely contact the website owner. They may not know your link was no-followed and would probably want to correct it.
