This is a great site for keeping up with what's going on. The plays are broken into cycles. This is especially good for research as it includes essays and miscellaneous resources. This is a book club with plays, references, and resources. This is a site for an offline magazine, but some of the essays and interviews are posted here, and they intend to archive on the net.
Subscription includes a membership that has ticket discounts all over the country.
If nothing else, drop them a line, and they'll send information. The magazine often includes complete scripts. This is a great magazine for the rest of us, as it falls between high academia and fluff. Used under License.