The memoir is fantastic. I'm currently reading a volume of his letters—1984—and it provides a similar thrill as 'Motion of Light in Water', even if he occasionally riffs on culture at a level far beyond what I can follow.

Regarding Dhalgren, it is absolutely worth the read, and rumors of it's impenetrability have been greatly exaggerated. That said, it is not where I'd start (if indeed you're starting with it). For SF: Babel 17/Empire Star. Or the Neveryon series. If you're okay with very explicit (but wonderfully written) sex scenes…