When the beer has reached its final gravity you're going to "oak" it. Here's the lowdown:
Find yourself some "Heavy Toast" American oak chips. For a 5-gallon batch, fill a glass 1-cup measure half full with the oak chips, and then top it off with near boiling water. Throw this in the microwave for a minte or so, or until the water begins to boil. Remove and cover with a piece of aluminium foil, keeping it as sanitary as possible. Wear a heat-resistant glove when handling, and be careful, it's HOT! Let this sit for a while to cool down.
When the oak juice tea has cooled, add the juice and chips directly to the primary fermenter; or if you have the luxury of a secondary fermenter, add it to that after you've sanitised it and purged it with C02. After adding the oak, chill to 2.2°C for one week, then keg or bottle and enjoy!