Question

How do you really check the Quality of a Directory? Or how do you figure out a Quality Directory?

Answer 1

I usually check the pagerank and the indexing of the web directory before submitting my site into it. Also, it should have a good navigation for the visitors.

Answer 2

Mozilla Firefox has some awesome addons that give you page rank,alexa,page age,dofollow and nofollow. Here's the one I use I keep it up on my navigation tool bar.
Live PageRank 0.9.6
There are more tools out there that work just as well.
You'll have to do a little search.
Good Luck!