Great score 2005...I have the same unit I purchased a couple of weeks before Thanksgiving last year.
You'll have lots of questions and here's the place for the answers. I just put a new door on my MES40. I'll be able to help you if you have any leakage problems with the door, that's for sure.
You'll want to make sure and have some thermometers. You need to test the probe in the MES with boiling water and compare that to another thermometer so you can calibrate them. Also, there are spots that are hotter than others. Read as much as you can on this site because a lot has been written about them.
You also need to consider smoking with dust and pellets. You'll have questions about dry or wet chips, dust, pellets, flavors and the list goes on.
While your seasoning the unit check your temps and during the last hour check out the wood seasoning. You might want to pull the bottom vent out about an inch after you load your chips. You might also want to pull the chip tray towards the door about an inch. That will give you more draft. Leave your top vent wide open all the time and if you have another thermoter on a wire, thread it down through the top vent.
Most importantly, don't forget to take pictures!
Good luck and happy smoking,