If you haven't checked them out already, you should know about the Wounded Warrior Project. 

The Wounded Warrior Project fosters the most successful, well-adjusted generation of wounded service members in our nation's history. Not only do they raise awareness and enlist the public's aid for the needs of injured service members, they help injured service members aid and assist each other. 

The Wounded Warrior Project also provides unique, direct programs and services to meet the needs of injured service members. 

Here's a link to the website. Go check them out and show some support!