iTunes Backup - iOS & Settings only - No Apps
Short Answer
Back up to iCloud and to iTunes. Then, delete the Mobile Applications folder from Windows Explorer/Finder to remove the apps that have been backed up to iTunes.
Long Answer
Make sure you read the Apple support page before you get started, but basically, I would recommend backing up to iCloud, which says that it will automatically back up your camera roll, accounts, documents, and settings. Then, do a full backup to iTunes by clicking Back Up when you plug in your iOS device. and you can remove the folder Mobile Applications on Windows or Mac by navigating to the Users\Music\iTunes\iTunes Media\Mobile Applications folder (actual folder names may vary based on operating system).
Pictures
Deleting the Mobile Applications Folder

Look at the directory path at the bottom of the picture, too.