I"m looking for a book that will help me (as a sysadmin novice) learn about how to administer a 10.5.x Leopard Server box, akin to "The Complete System Administrator."
PeachPit has complete books for Leopard Server (though I would consider looking at the Snow Leopard Server books when they get out - they probably will cover newer technology and will have much of the same stuff targeted at Leopard server as well) - they are aimed at getting Apple certification (Apple uses them for coursework I think), but they are a great resource.