I want to call attention to a recent post on the LXX here. Larry makes some great points about the neglect of the LXX on the part of students of the NT and then points us to some very helpful resources.
The only question I have is, what is the edition of the LXX that NT students and scholars should use for their research? A list of the available critical editions of the books of the LXX may be found here at the Septuaginta-Unternehmen's website (23 volumes; 2/3 complete). Many, if not all of these volumes, are available through Logos software as well. Volumes of this series not only (1) reconstruct the Old Greek but also (2) catalogue the available evidence of the reception history in a second apparatus. (3) The Orthographica und Grammatica section helpfully lists the types of scribal errors which occurred in the manuscripts used for the production of the edition (helpful for LXX and NT scholars alike). If you are studying the relationship of the LXX to the NT, then start with the Goettingen Septuaginta. If there is no Goettingen volume, then use Rahlfs or Brooke McLean.