The first thing I'd suggest is to buy a book called
"Doing it Right, The Fundamentals of Better Diving" by Jarrod Jablonski
JJ is the founder of GUE which is the training agency for DIR and that particular book will help you understand what DIR is all about, from the mindset to the equipment, it's an excellent reference, although it only touchs on the fringes of serious DIR techniques it is without doubt the book to introduce you to the information you currently seek.
Secondly I'd try and link up with some DIR/GUE guys, YD has a fair few now and we're spread the length of the country so I'm sure that you can get a dive or two in with someone who can show you the ropes wherever you are in the country.
GUE has only one instructor in the UK at the moment, a guy called Andy Kerslake... Andy is an absolute gent and an excellent instructor, he's currently taking a couple of YD members through Tech 1 (Wetlettuce & Mark Emery) so these guys can give you a good heads up on AndyK's capabilities if you're in the market for some GUE instruction.
Of course I'm sure that you've already found all of the relevant DIR/GUE links on the Internet but if not let me know and I'll post you some good ones.
HTH and welcome to the darkside...
Rgds
Dave