I wouldn't do anything. My MINI sits for weeks at a time without being driven with no problems.
If I were going to leave it for a few months, I would put a battery tender on it and put it on jack stands to keep the tires from getting flat spots.
A battery tender or float charger, is a little battery charger that puts out less than an ampere of current, it maintains the battery's charge if it is not used for a long time. It is only to be used on a fully charged battery.
It probably wouldn't be a good idea to disconnect the battery for a month, the electronics on board need a little electricity to remember things.
When not in use, the battery discharges a tiny bit every day...
Things like the computer, keyless entry, etc use a bit of power in standby.
A month should be ok...but if you do it regularly, get a battery tender.
I'd just cover it and leave it... Or, if no cover, just dust it off before you leave. That way you won't have that extra month's worth, on top of what you already have, when you get back.
As said previously, a month is nothing to worry about, just park it and go. My car sits all winter, 5-6 months, and all I do is dump a can of seafoam and fill the tank before putting it into storage.
