The answer is completely dependent on the individuals personal goals. For general health, you need 30 minutes of activity most days of the week. For weight loss you need to be doing 60 + minutes of activity everyday. Do a lighter workout the day after a hard one… meaning if you run and do weights on Monday, just go for a walk on Tuesday.
I encourage my clients to stretch during and after a workout so that they do not forget to do it! Stretching can and should be done daily.
Most important, listen to your body and know the difference between being sore from a workout and pain. Being sore is good… being in pain is not.