Do a Google "Link" Search

Search Google's Advanced Search feature to try and find related sites that will allow you to add your url.
Enter your primary keyword or keywords plus the phrase "add your website" or "submit your link". This will help you find relevant websites that will allow you to leave your link.
Tips and Resources
1.Examples of this type of search would be to type the following into Google "allallintitle:add+url "your keywords" or allinbody:submit+your+link "your keywords"