One place that I've linked to rather often is The Immanent Frame, which offers some fascinating posts from a number of authors on secularism, Islam, evangelicalism, and religion in general. There have been a long string of posts recently on the Immanent Frame about evangelicalism, and I've linked a few of them here on Clavi Non Defixi. I must admit, I don't know why evangelicals are so damned interesting all of the sudden. Rhys Williams asked the same question in his recent post "Why do we want to know?", and I think it's good that the question is asked rather than the answer assumed.
Williams discusses how a lot of interest in evangelicals is simply the result of politics and elections; they are the constiuency du jour. He also offers an interesting comparison of current interest with studies of "American Catholics" in the '60s and "fundamentalists" in the '80s and '90s. And in the end he doesn't leave us with too much hope for discussion of "evangelicals" by interested outsiders:
Thus, at least in an election year, when elected officials, aspiring candidates, consultants, and media all have a lot at stake on shaping their appeals effectively, this practical outcome seems to me to swamp the scholarly concerns scholars have with precision and definition. If we want to know who evangelicals are, how many there are, and what they believe and how they practice, I am all for precision, nuance, and variation. But if we need to know how “they” are going to pull a voting lever regarding an either/or choice in a divided electorate, it seems to me that the global term bandied about in the media tells us what we want to know.