My Grandfather told me years ago that FALL was the best time to plant trees. Early spring is the next best time. I have planted during both times and I have to agree with my Grand Father that FALL is the best time.
Depending on your local, right now may be the best time to pick out your trees, even if you can't plant until spring.
If you are digging your own, and fall color is part of your plan, watch when the leaves start turning color. What looks like a great tree, may be, but it may not have the desired color you strive for.
If you are not planning to plant until spring...Mark the tree with a ribbon. If you have several trees that you are transplanting, make a note on where you want the tree you are planting. It is easier than trying to remember in the spring when all you have to remember is a bare stick.
If you are planting a tree from a nursery, visit now. Most have areas of planted trees and you can look and compare the colors. Then ask the staff to mark the trees SOLD to be picked up in the spring. It is also a great time to schedule a tip for them to plant them for you also.
A little forethought now will help you achieve the desired fall look of your home and the 'envy' of your friends and family!