Welcome to the SMF Family. I am a little surprised they didn't give you a better price on the floor model. $350 is the regular price. Anyway as far as the Ribs go...
A full rack of Spare Ribs will take about 6 hours at 225*F...The 3-2-1 smoked rib recipe is a good way to smoke ribs and tends to turn out perfect ribs every time whether you are using the meatier Full rack spare rib or the Saint Louis cut. Baby Back ribs use a 2-2-1 method. The ribs are smoked at 225 - 250 degrees for best results...
The 3 stands for the 3 hours that you initially smoke the ribs with nothing but your favorite rub on them and some smoke with your favorite hardwood such as hickory, apple, pecan, etc. After the 3 hours you remove the ribs and quickly double wrap them in heavy duty foil.. just before you seal them up add some Foiling Juice or Apple Juice and close the foil leaving some room around the ribs for the steam to be able to flow around the meat and the juice to braise the meat which Flavors/Tenderizes it.
The ribs cook in the smoker wrapped for 2 hours undisturbed. There is no need for Smoke at this point... After 2 hours remove the ribs from the smoker, unwrap and place back into the smoker for the final 1 hour, with smoke if you wish.This firms them up, creates a nice Bark and finishes the cooking process. You can add a glaze or sauce at this point if you like. The meat will be pretty close to fall off the bone and be extremely juicy, tender and flavorful...Try the Foiling Juice.
Chips will last about 30-45 minutes. Don't add more than a small handful, about 1/4Cup, or they may start to Puff Flames out the chip loader. This frequent reload is no big deal on a 6 hour rack of ribs but when you are smoking a 10Lb Pork Butt for 20 hours you are going to want an AMNPS Pellet smoke Generator. It will give you about 10 hours of Thin Blue Smoke (TBS) on a single load... http://www.amazenproducts.com Todd also has the best price on the Maverick 732 Duel Probe Remote Thermometer. Masterbuilt measures smoker temp just above the heating element. You wan to know and set the temp on the rack where the meat is. The MAV measures smoker temp an meat temp and sends the info to the remote up to 300' away.
With the ribs the 3-2-1 method will get the ribs very tender maybe even fall off the bone. You are looking for an Internal Temp (IT) of 145-150°F in the Ham. This will make it hot but not dry and stringy.
The MES40 is a great smoker. I have 2 and there are hundreds of owners of them on the forum. I believe Academy only sells the all stainless steel model # 20070311 That is the 1st Gen of that style and although temps may be up to 20°F off when you compare what the MES say and what the MAV says. Check the MAV in Boiling water, if the temp is around 212°F, depending on your elevation, you then know the MAV is accurate and go by it to set your cook temp. Keep the Exhaust Wide Open when the smoker is running. I believe you can read the Manual on the Masterbuilt site and their customer service is pretty good. Call them and request a manual.
Good Luck and enjoy your new toy...JJ