PragProg just announced that the print version of Deploying Rails (written by me and Tony Burns) is being shipped out. The book dives into Puppet, Capistrano, Vagrant, Nagios, Ganglia, and all that sort of devops-y stuff. Enjoy!
If you're using Passenger you might want to set PassengerMemLimit to keep memory usage under control. But the original patch is 4 months old and no longer applies cleanly. So I posted an updated patch with some notes on installing it and using the PassengerMemLimit directive.
Here's a little code written by Rich Kilmer that gets Sphinx, Riddle, and will_paginate to work together nicely. This is handy if you're not using one of the Rails plugins but are just using the Riddle API directly.