There aren't really any requirements to speak of, but the more you know about networking, the better off you'll be.
Classes are out there, but they are not on a common schedule. You have to be in the right place at the right time to get into one. Classes run usually around $3000.00 or so. I got a deal on mine, it cost me around $2100.00.
Classes are 9am-5pm for 1 week; info on EC-council website says you do the exam on the last day of class; that would make it a "boot camp", but that's not what happened with me. Last day of class rolled around and we weren't finished with courseware yet. Besiides, where I did the class, they didn't offer the exam. I had to travel to Westlake Ohio to do the exam; the exam is not offered there anymore for some reason.
Class is very cool; it teaches about Enumeration, how to write Trojans and viruses, SQL Injection, Honeypots, DMZs, hacking through Firewals, destroying hard drives, ADS (Alternate DataStreams), “Mary had a Little Lamb” Formula (Not in the class I took); Hacking web servers, Hacking Wireless, How to steal files using Word Documents, Cryptography, MIPS-years, destroying Norton (yay!), MacAfee, etc. See full details on courseware at http://www.eccouncil.org/EC-Council%20Education/ceh-course-outline.htm
You will need to sign an agreement saying that you will not hack systems and that you will be "Ethical". If you don't, and if you do hack someone's systems, you can put yourself in prison.
I did my class in July 04; passed exam in Dec 04; EC-council says on their website that they came out with the CEH "ver.4" courseware about May or April 05; I don't know if there is a big differance between what I did ("ver. 3") and this new ver. 4. But once you achieve the CEH cert, it's supposed to be good for "life", in that it doesn't "expire" and "retire" the way Cisco and Citrix certs do.
Oh yeah, You also need to know how to de-obfuscate a URL, something tht was NOT in the class I took. But it is really cool; there's a website that does an excellent job explaining it. This WAS ON the exam, not taught in the class I took.