I'm not sure there's a quick way to get into Autechre, their whole discography is like a trajectory, a slow descent from relatively standard early 90s Warp ambient (Amber) through mechanisation (Tri Repetae), into chaos (LP7-Confeld), out of which patterns start to emerge (Quaristice on) like how if you stare enough at a field of static you start to see faces. I can't imagine coming to any of their later stuff out of order, or out of the context of the music of the time.
Fredd-E posted a good list of tracks earlier, and everything up to Tri Repetae is kinda approachable on its own. After that I dunno, the Quaristice Quadrange EP is a good listen, because it's got the chaos, but they're jamming around with the same material so it's easier to see the thought processes and the patterns in it.
Perversely, it's a bit easier to approach when someone's done the unpicking for you. They did a video for Gantz Graf that has CGI synced to the parts and the effects
http://www.youtube.com/watch?v=AyJfHU4GoOQ that shows how it develops. I actually prefer the unofficial visualisation for plyPhon
http://www.youtube.com/watch?v=acuwRHIWL_o
But it's hard music to listen to, for sure. You have to be in the mood for it, and if it comes up on your random playlist you have to constantly explain it to people.
