You may have noticed a stickied thread at the top of the the forum called "Looking for a Guild? Start Here". As that thread suggests, you can get a summary of every guild on the server, when they play, how serious they are about raiding, etc. all by going to this page:
http://wiki.project1999.com/Guilds:Guild_List
To try and get that same info from this forum you'd have to visit every guild's thread individually, and even then many of them don't include all the details that are on that page.
After you've looked at that page though, and identified a few guilds whose play time/style matches your's, then this forum (and the guilds' webpages) are a great way to learn more about them.