bourbon barrel stout

I have had a few bourbon barrel stouts at a local comedy club and woud like to give this a try. I have done a few stouts already but never added oak or bourbon. I have ssen that most people soak oak cubes in Bourbon but how long and when to add them to fermentor do I add any bourbon also? Do the fit in a 5 gal glass carboy? Has anyone done this any help would be great

I did it awhile ago. I soaked 2oz of oak chips in makers mark for a week. Then I drained the makers mark, discarded it (ie. drank it - had a strange woody taste). I believe I put it in secondary for the full 2 weeks. This will make a nice sipping beer. Dont add any bourbon to the beer aside from what has soaked into the chips.

I soaked 2 oz of heavy toasted oak in just enough Jim Beam (Black I think) to cover it and soaked it for about 3 weeks while my stout was in primary. After primary I transferred to secondary for a week then added about half the oak chips for 2 weeks before bottling. If you don't primary you could probably add the chips just after fermentation ends. It added some nice oak-vanilla flavors, I think it worked out really nice.
I keep the remaining oak chips around and throw them in a commercial brew that I'm thinking of adding oak to, to see if I'd like to try a recipe in the future.

Will the cubes fit in a glass 5 gallon carboy

Yes they will they are pretty small if some are not you can always break them apart.

Northern Brewer has a great Oak Bourbon porter extract kit that comes with 2 ounces of oak cubes. I soaked them in a pint of Makers Mark for a week, then dumped it all into secondary and let it sit for a week before I bottled. One of the best I have done!