Either partially shut down which means setting a temp of 55 degress, or fully shut down which means turning off the heat. There is no 'inbetween' shutdown temperature like 35 degreese. And with EITHER shutdown method, there are things you need to do and things you don't need to go. Here are some guidelines.
If you're completely shutting down:
Turn the heater off. Drain ALL the water from ALL your plumbing (including toilets, hot water heaters, indoor piping, etc.). Unplug every appliance in the house. Throw away or dispose of all perishable foods.
I suggest that a plumber is best recommended to completely drain your system at least the FIRST time you do a complete shutdown. Draining the plumbing for a total shutdown can be tricky since toilet bowls, drain traps and other 'things' hold water. These parts require treatment with a non-toxic antifreeze, preferably of the 'automotive type'. AND, when you hire your contractor, tell him you want him to SHOW you how to do everything. This, of course, will affect your bill. However, considering the expense of missing one thing or making a mistake, it could cost you a whole lot more.
If you're doing a partial close:
Set the thermostat at 55 degrees. Do NOT drain any of the plumbing. Turn off your water heater and drain it. Some of your appliances can be left on, but you should still check them on a regular basis.
You should also check the house regularly during extreme cold spells to make sure the house is warm enough to prevent freezing pipes. Failing to do so could prove costly.
In either shutdown situation, it may be a good idea to hire someone, a neighbor or not, to regularly inspect your property. You will need to decide if your hire should have a key or not. The most common problem resulting from improper shutdowns are water-related. Please heed my advice on hiring a plumber the FIRST time you do a complete shutdown IF that's what you're doing. For more details on shutting down completely or partially, contact the Water, Sewer, and Energy Suppliers / Utilities in the area in which the home being shut down resides.