I just read authors that give away the first book in a series. I find it gives me a good idea of their writing style and whether it appeals to me or not. Often those books are ones people have linked in the deals/freebies forum or baen library too
That's not a whole lot different from how I used to find new authors when I bought paperback books, only rather than the first book in a series been free, I'd borrow it from a friend