Plant them in the ground as soon as they arrive.

Even though we are going down to 20 degrees at night?

Plant them after the 20 degree temp and then cover on subfreezing nights if they have leaves. I order maples from Forestfarm. They send them in tree tubes and gallon containers

I am assuming that your trees will still be dormant and NOT have leaves. If so, yes, plant them regardless of the temp, they'll be okay. If they have leafed out already (or are just about to when you get them), then yes, as steve nj says--you will need to protect them somehow (cover them or more them into a cool garage for a couple of days.

Thanks. I expect them this week. I have 3 large pots I will put them in.

How much water should I give them after I plant them in the pots. I got 3 large ones today and got them all planted. I might even keep them in the pots for a while to see where is the good place for them. I figure that way I can move them easier till I get the right spot.

I would suggest that you decide now where you want them and plant them. This is a great time to transplant a deciduous tree (before the leaves emerge). After the leaves emerge and temps start to rise, things get more stressful for the plant. You still have a couple of weeks. If you really need much more time, I suppose you can always leave them in the pots throughout the summer and plant in the fall (another good time to transplant).

The leaves have already started to come out. That is why I am keeping them in pots and bringing them indoors at night. I want them to get use to the weather here and unravel from shipping.