Ok, what I meant for the stretching is the general stretching I think people should be doing every day, no matter if they are working out or not.
Specifically, for lifting or cardiovascular activity, it's always best to stretch- before your exercise, spend about 5 minutes doing light physical cardio activity to slightly elevate the heart rate and warm up the muscles, then stretch. Spend 15- 20 seconds holding each stretch. After you conclude your exercise, stretch the muscles again, holding the stretch 20- 30 seconds. You don't need to worry about the light physical activity, as the muscles are warmed and stretched from the activity.
As far as the stretching I advocate doing every day for 30 minutes- doesn't matter if you do it in the morning or at night, although I would hypothesize that if you stretched in the morning, your muscles will be a bit stiffer, so you may tend to be less flexible in the morning than if you waited until the end of the day. This is just a hypothesis- but I generally feel less stiff in the later part of the day than the earlier.
Does that help?