+1 to bus above. I think you get the best flavor out of them by soaking them in liquor or some type of wine first. That generally takes only 1-3 weeks and then they can be directly pitched into your beer. An ounce can be good in 5 gallons of beer, but you may need 4-8 weeks of contact time. Taste weekly once you get to 3rd or 4th week. Also remember that the oak "presence" in your beer will fade over time.
After coming out of beer batches, I put them either into a batch of sour or store in the freezer for eventual sour duty for the same reasons given above.