Plan the Trip in Advance
Make sure that you have some sort of plain place before you visit. You should know the timings of operation. The museum is closed on Mondays so do make a note of that. It is also closed for Thanksgiving and Christmas. If you are driving, get directions in advance and if you are taking a bus, do know which bus will get you closest to the museum. Parking is available at a price of one dollar per hour as well.
You will probably be spending the whole day in the museum so make sure that you are ready for plenty of standing and walking. Wear comfortable clothes as well as comfortable shoes so that your legs and ankles do not hurt midway through the day.
Presence of 68000 pieces of art quite simply means that you cannot see all of them in a single day. If you wish to have a close examination, probably a week will not be enough. Make sure you know about the specific areas of your interest and what they hold. Prioritise your particular areas of interest and once you are able to see these, you can move onto other areas that you may not have the same level of excitement for.