He writes books aimed at young adults and is most famous for the Northern Lights series
Amazon.co.uk User Recommendation
These follow a rough structure and allude to much of Milton's Paradise Lost:
http://en.wikipedia.org/wiki/Paradise_Lost
And are generally considered a pretty good read. He mixes some nice sci-fi ideas into a fantasy setting - I guess some of it is almost steampunk really?
Certainly worth a read, even if you're not a "Young Adult" any more :) At worst you'll know what people are on about on the next quiz show that references him.