Welcome!
Well, I know that you should put it in the room in which it is to be installed, if at all possible. Lay them flat, but up on some 2 x 4's to prevent trapping any moisture. DO NOT stand them on edge or leave one side exposed and the other not. After allowing them to aclimatize, you may wish to take advantage of your down time to add some extra coats of Tung Oil to the surfaces--both sides and the edges is ideal.
You can get 100% Tung Oil which is food safe, easy to apply and completely non-toxic at
Lee Valley. A lot of oils that you find in big box stores, etc. are cut with other oil or drying agents. Lee Valley is a Canadian, family run business with an excellent reputation for quality service and excellent products.More information than you asked for, I know, but I've been preparing my holiday shopping list....

. You can also get 100% Tung Oil at
Rockler, another fun place to shop, and
Woodcraft, both of which have stores in the US.
What cabinets are you installing? We are a nosy lot, greedy for details!
Susan