In 1982 dad and i logged cottonwood for a fealla that sawed it into lumber for flooring for truck beds for Fruehaf <sp> We kinda thought he was crazy, and it turned out he was on the right track but it just wouldnt dry..... that fella tried to get me to buy a sawmill and a few years later i did, and i tried cutting a long log load of cottonwood into 2 inch lumber for another fella..... I learned in a hurry that dull teeth on a cottonwood can heat the blade up in less than 8 feet, I thought i had warped the then $750 blade for good, but it sprang back after about 15 minutes of idling it and it didnt even lose its tension. I did make a 4x10 out of that 2x10 if a person could call it that... thick and thin all over it was......
Grandad made a double tree out of cottonwood one fall, a nieghbor told him it would never work very long so he threw it up in the loft and forgot it for a couple years til one spring he broke several double trees, and the only one left was the cottonwood one, he used that warped old piece of wood for several years and never broke it, and when they bought the first tractor it was still being used so after about 60 years of no use it still hangs in my uncles barn a testimny to the strength of a tree cut long ago.
Cottonwood will warp like crazy when cut, as it has so much moisture and there is really no way to control the moisture as it leaves, but if your trees are small, and you have them up off the ground ad are using them after drying for awhile you may get away from the excessive warpage..... but dont count on it! when brought inside they will continue to dry out and will bend and warp as they please, and make a better conversation piece for it!!
Have fun making your furniture!!! It will last a lifetime and then some!