I found two great websites!
The first organization is called Operation Homefront. It coordinates the adoption of military servicemembers AND their families!! If you are looking for other ways to help support our troops this is a great way to do it!
The site is set up so that you can search for a military person or a military family using criteria that lets you choose things like branch of service, location, etc., about the person or family you are willing to adopt. A list of things they like and/or need is shown to help you get a better idea of what to send then it automatically brings you to an online store with pre-made care packages and individual items. Everything has somewhat of a discount and it ships to both domestic and FPO addresses. You have to buy directly from them. They will not give out addresses for those who have registered to be sponsored on their site.
I registered the Old Man, but I had to enter some personal information. If you are interested in using this site to sent things over, leave a comment and I'll email you the information on how to look him up!
If you'd like to browse or adopt a service member or family member, visit E-CarePackage.
The second site has great pre-made care packages! If you buy packages from them, you can send it to yourself to send overseas or send it directly over to the Old Man. They ship to military addresses! If anything, you can browse the site to get a few ideas on what to send!
I believe that for purchases over $20, shipping to domestic addresses is free! Please visit Minimus Care Packages.