Pretty much through Google the first couple of times. But those were more of a just dripping in to check something visits.
Became more active after deciding to get a e-ink reader, and followed a lot of links down from blog's like JKontheRun, etc. when trying to decide which one to get.
Still, Mobileread has become the No 1 site I send people who show an interest in E-books and readers to.