Wait until you think fermentation has stopped, take a hydrometer reading and if its close to .990 its done, if you don't have a hydrometer wait until you only see a bubble every couple of minutes (hydrometers take the guess work out)
Leave it for a further week in the same DJ, this allows the yeast to clean up after itself (failure to do this can lead to your wine giving you a bad head and possibly the s***s)
After this additional week rack into a sterile DJ onto a crushed campden tablet and add stabiliser (also called fermentation stopper) then degas, you can do this by either covering the neck of the DJ with a clean hand then shaking the DJ and releasing the CO2 (you have do this several times over a couple of days) or you can do it in a couple of minutes using a drill and degassing wand, you can buy these at home brew shops or make your own from a plastic coat hanger as i did, there is a video on how to do this here -
http://www.thehomebrewforum.co.uk/showthread.php?t=48971
.