“Scientific Stretching” book and tape by Kurz and/or “Relax into Stretch” book/dvd and “Forced Relaxation” dvd by Pavel will all point you in the right direction if you want to get into a full side split in less than 3 years.
Side split is one of my three primary physical goals right now and I’ve been doing a ton of research. I’m no where near there yet but you can read about my progress to a full side split (my goal is by mid December) among other things on my blog and also on Tao Bums if you are bored enough.