Kozelek has a wide range of material -- not as much as Steven R. Smith, but still relatively diverse -- so I'm not sure what kind of starting point I'd recommend. Check out songs like "Katy Song," "Void" and "Duk Koo Kim" to get some ideas of his material.
In short, I would rank Mark Kozelek up there with Toby Driver, Richard Youngs, Aidan Baker, Ben Chasny and Fennesz as some of the most important individuals* in today's generation of music. If you are unfamiliar with any of them, you would do yourself a huge favor by checking them out.
*Not including recently passed away musicians, such as Elliott Smith and J Dilla.
I just never really went for Husker Du, even when I was really into punk and its off-shoots.
Mark Kozelek has released some material under his own name (including an acoustic cover of AC/DC; I'm not sh*tting you), but he's famous for being front man for the Red House Painters (indie/slowcore outfit of the 90s) and Sun Kil Moon (a sorta indie band of the past decade; two original albums, with one bizarre Modest Mouse cover album). I'm not sure what genre I'd definitely put his music under; certain albums veer certain ways (slowcore for early RHP work; folk for some of his later stuff). Guy had a rough life growing up -- which isn't unique, really, but it's really reflected in his voice, especially on Songs for a Blue Guitar and onwards.
His lyrics are just unbelievable. Phenomenal imagery with a kind of economy of ideas that's really not paralleled; there can be comparisons to Elliott Smith and Nick Drake, but whereas those two were rather upfront with their anguish, Kozelek sounds reflective, and almost resigned.
getting ready to go back to college; first quarter was pretty cool. been listening to mostly jazz and classical recently, and going through a few of my favorites from metal and rap. reorganization has also been a bit of a *****.