If you're going to use the chips,I'd say 3-4 oz would do it. If you're going to soak them in bourbon or the like,I wouldn't use more than 3 jiggers mixed with the chips in an airtight container. I put that mixture in the fridge for the entire time the ale was fermenting.
Then poured all through a hop sack into secondary,tied off the sack,& dropped it in. Racked the ale onto them & sealed it up. Let it sit for a week,then take a shot glass size sample to see if it's at the level you like. Adjust aging time according to those taste samples. Then rack to bottling bucket & prime.