My mom sends my cousin (Army) Costco-sized boxes of beef jerky which he then barters with other guys for things they may have received (Pop-Tarts, granola bars, etc.) When my husband was deployed, my mom sent him a huge box of See's lollipops. They were a smashing success, and made him a very popular dude. On that deployment, my husband was gone over the holidays, and I sent him a holiday package with Christmas decorations (maybe not a good idea if your brother isn't in a hardened facility) - a small tree and itty-bitty ornaments, a string of lights, some tiny stockings. I also sent a Santa hat and a headband with reindeer antlers, and a list with my own "12 days of Christmas" which had twelve different challenges (like decorate the tree, hang the lights, get a picture of you in the hat and one of your friends in the antlers). He took pictures of each "task" he completed and mailed them home. While it may seem lame, he said that it gave him something to think about other than what they were in the middle of, and his friends enjoyed the little bit of festivity it brought their encampment. I also sent videos - Indiana Jones, X-Men, box sets of Hogan's Heroes and Dr. Who. Just remember that whatever you send will either have to be consumed, carried home at the end of the deployment (space is VERY limited) or abandoned. (My little Christmas tree and it's ornaments never did make it back, nor the antlers, but the Santa hat did.)
Whatever you decide to send, please know that the Post Office has special boxes and discounted rates for packages for our troops. The Post Office can only guarantee second day or priority mail to the APO office on the West Coast or East Coast. After that, the packages are palletized and will go over as soon as possible. However, since all the mail goes over on military aircraft, the mail pallet may be bumped for extra food or ammunition or something else deemed more critical than care packages, and may take longer. I've had stuff get there in less than a week, and stuff get there in 6 weeks. If you send your holiday packages by mid-November, they should get there before Christmas.