I never start with more than about 50 lit. I find that 50, when at their hotest, will get me to about 450 or even higher. If I am looking for about 350, for example, I dump the lit, arrange the coals, add the grate and close the lid with all vents, top and bottom open. After about 10-15 minutes, I brush the now hot grate clean and add the food. If the fire is too hot for the food I'm cooking, I'll close the bottom vents by half and the top by no more than half.
I like to do most chicken about 400, pork tenderloin (direct) about the same or a little lower and for beef it depends on the cut and the time involved. I go direct on just about everything if the time will be fairly short, indirect if longer, but again it depends. Things like steak and hamburgers I go direct or maybe a combination of direct and indirect. I always keep the top vent over the food. Also, I dump the lit when about 80% are going.