Source: http://www.highervisibility.com/finding-niche-directories-and-how-to-use-them-to-your-advantage
while directory sites can be easily flagged for spams and poor quality content, it does not mean that all directories should be off limits. To help you select the most reliable directories available, check out these tips.
Niche directories that you can benefit from
How to Discover the Right Niche Directories
– Type the top keywords on your site and add the word “directory”
– Use SEOQuake to sort directories by “links” or “indexed pages”
– You should never be asked to give reciprocal links
– Good directories are those that have engaging website design and not just a long list of links
– The more recent the dates on directories, the better
– Look for other businesses listed on that directory, if it looks spammy, avoid that directory
How to Build Quality Links on Niche Directories
– It’s important to engage with the directory as much as possible
– Get involved with comments or submit an article for visibility
– General directories that are still good for link juice: Yahoo and DMOZ