At my library last week, I pIcked up a copy of "Extra Innings" from Baseball Prosepectus. It is well worth reading. The parts I really enjoyed were related to use of bullpens and how to construct a bullpen. In the section on constructing a pen, there was some great information on cost per WAR for by position (starter, reliever, fielders) and variability from one year to the next. It was really enlightening.
I'd do a full review, but I'm, uh, booked right now at work.
And if you do not have a card for your local library, GET ONE. Remember: you are not a Braves fan, and you can read.