I heard once when I first started out hunting that you should be able to draw and hold your bow comfortably for roughly 1 minute. If you can' t do that, you' re shooting too much weight. I' ve pretty much stuck with that ever since.
The longest I think I' ve held on a deer where I actually got a shot was about 20 seconds, no more than 30. I' ve found that if there' s a reason for me to be holding any longer than that, chances are I' m not going to get a shot. On average I would say I draw and hold just long enough to get my pin settled in place before I realease, which is proably only 10 seconds or so.
As for when to draw - it depends on the situation. You generally try to wait until the deer is facing away or it' s head is obstructed from view so it doesn' t catch you moving. Although I' ve found that if a deer is not spooked and just casually feeding or walking through the woods, you can get away with a lot of movement when drawing without getting spotted. Now you don' t want to go doing jumping jacks in your stand to test that out, but I' m sure you understand what I' m saying.
