Uncover the Net: Web Directory - This is a new web directory launched just this last week. As it is new, it doesn't have a lot of listings yet but it is quickly growing.
This site does charge for listings which can be problematic for finding non-commercial sites. (I railed against this practice just a few posts back for this at some other sites.) However, I have been in contact with the site owner and he has been very amendable to adding free listings for sites which are primarily non-commercial and information packed. This could turn out to be a great directory. Look it over, come back a few months from now, and check it out again and see if it is a decent resource.