When it comes to genre stuff, I'm doing a lot of following authors I like on twitter (entertaining in itself) and then paying attention to both what other authors they end up chatting with, and the things they mention reading and liking. A fair amount of this is short fiction that is available online, which is then a good taste test for if I should seek out longer work.

I still read the backs, at least, of a lot of books on the big paperback display in front, if the cover is at all intruiging. A lot doesn't pass the first 10 page, test, though.

I like the "Big Idea" series on Scalzi's blog also.