I've oaked this recipe and it is awesome!!!
Your homebrew shop should sell oak chips, probably in 4 oz and/or one pound quantities. It's really more of a wine-related thing, so look in the wine making section at your LHBS.
After primary fermentation is done, rack your beer into secondary as normal but add some oak chips. Let the beer sit in secondary for a week or so, the fewer chips the longer it can sit. If you think you can bottle in a week, go heavier. If you prefer to let it sit in seconday for a few weeks or longer, use less. I used 2.5oz Toasted American oak for one week. The oakiness was very well pronounced and the next time I oak a beer I'll shoot for one ounce for maybe two weeks in secondary. Even after 6 months the oak is very dominant at these quantities (haven't tried one in a couple months)
Some people say to soak your chips in bourbon to sanitize, or to boil them. I did neither and got great results from a clean bag of chips that had been open and tightly re-sealed for a couple of months.
Ultimately i would advise to start with a small amount of chips (say, an ounce to five gallons) and go from there. Hope this helps, and please post your results if you try Oaking the Bastard!