A comparison of extractors in terms of tradeoffs between time, randomness and space ?
The default reference is Ronen Shaltiel's survey.  This predates the important results of [Barak-Impagliazzo-Wigderson '04], [Barak-Kindler-Shaltiel-Sudakov-Wigderson '05], [Barak-Rao-Shaltiel-Wigderson '06] etc.  I believe Anup Rao's Ph.D. thesis is a good recent reference that describes these developments.