All, I'm going to rack 3 beers to scondary today (going from bucket to carboy). The beers have been bubbling away in primary for a week (though the bubbles have all but stopped) and we are racking to free up the buckets for bottling at a later point.
Should we be trying to aerate the wort at this time to kick the fermentation up or should we be trying not to introduce oxygen into the wort?
Check the FG, to make sure the fermentation is finished before you rack.
When you rack, you want to siphon very quietly, to prevent aeration. Oxygen at this point will ruin the beer. I like to make sure the tip of my tubing is in the very bottom of the receiving carboy, and at a bit of an angle laying in the bottom, so it doesn't splash at all. You want the tubing to be long enough so you don't have any splashing.
__________________ Broken Leg Brewery
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At this point you have beer and not wort because it has already been fermenated. Introducing oxygen would ruin the beer. If there is any more sugar for the yeast to eat than they will take care of it in the secondary. One way to see if it is finished is to check the final gravity.