…besides the Septuagint itself, is this spot right here. It’s the Web presence of The International Organization for Septuagint and Cognate Studies (IOSCS). The IOSCS is “a nonprofit, learned society formed to promote international research in and study of the Septuagint and related texts.”
Membership in the organization is affordable (especially for students). They put out an annual journal (some volumes of which are freely available here), offer a yearly prize, and link to some useful LXX resources here.
The IOSCS home page is updated fairly regularly with news of publications, conferences, and other announcements. Check it out.