I am probably going to ruffle a lot of feathers for giving "kudos" to all the google-haters out there but they seem to have really done well with OKRs. I recommend checking out their online guide for some help with this. If you've got some extra time on your hands I also recommend reading "Work Rules!" by Laszlo Bock. He is the Head of People Operations (aka, HR Executive) at google and writes pretty extensively about how OKRs are used there and the success they've had with them.