I just went in and got both my technicians and general license the same day.
There's a link to a manual that will teach you every single thing you need to know. "No-Nonsense", everything you need to know and nothing you don't. It's a bit lengthy, but if you're serious about getting the license you will want to read every last paragraph to ensure you pass and have a good understanding.
There's a link to the actual exam they give you. You will be able to test your knowledge by taking the practice test (which is the same as the real test), but it isn't all the same