There are a couple easy things to remember when gluing up boards so that the resulting board does not warp.

First, make sure you alternate the growth rings. You don't need to be super-strict about this; you can have two boards with the rings oriented the same way next to each other if that results in a better looking finished board. But so much as it is possible, alternate the orientation.

Second, when you are finishing the board (if you are finishing the board), make sure that both sides get the same number of finish coats. If they don't, the surfaces will absorb moisture at different rates, and this can cause slight warping.