I'd wait to oak if you are using oak chips or some other oaking method other then powder. For my Merlots,Cabs, and pino noir's I like medium toast french oak. For big Zinfandels I use American oak. I usually wait until my third racking, the first racking being from primary, I let the wine clear well for at least a month with each racking if not longer. I steam my chips in a steamer basket for 10 minutes to get rid of the more bitter tannins (I dont boil like EC Kraus says) I start with 2oz except for my pinos I start with one ounce. I taste it with my wine theif every week or two and add more or rack it off if it's the flavor I like. You can always add and its hard to subtract so I prefer to go slow unless you like the taste of plywood in your wine. Good luck, Ken