www.tesall.com is great for jobs, lessons plans and also for links to the best ESL teacher's blogs all over the world - they were recently kind enough to feature a prominent link to my article about Tefl as a Missionary Language.
www.doyoutefl.com will soon be a great resource if you've left teaching, or if you've moved on to another school or country. It's basically a TEFL version of that site I've forgotten the name of where you look up and get in touch with old schoolfriends, and is just starting up, so obviously the more people who sign up soon the better. The people who run the site are extremely helpful at offering TEFL-related advice too.
www.developingteachers.com is a site more for serious teachers, particularly for people intending to Do the DELTA, like what I am. They have very detailed lesson plans to look at and use, and lots, and lots, and lots, of really useful teaching tips.