Warming up is tricky. I have read that if you are warming up you are doing ONLY one of two things. You are either -activating your muscles- OR -getting used to the weight-.
Therefore the first couple sets could/should be at low weights just warming up. 2-3 sets is fine at low weight. You want to be ready for your set as though it was a sport and you dont want to go in cold. Then, proceed to low rep sets where you are getting used to the weight. Sets of 1 or 2 is fine for this and you can slowly go up towards your weight. Jumps of 20-30 is fine starting at where you ended your warming up phase.
Also, light cardio(i cheat and do 3-5 minutes) is good because it will activate your nervous system somewhat.
Test deadlift, squat, chest and possibly military press.
as for your question, work up to your max, and then try doing singles at that weight until you cant do anymore. Then go home. You dont want to stress your nervous system on bench day because you have squats and deads later that week.