You can drag and drop the files to your usb drive, or select them all and go to send to. Flash drives are better if you have less files (last longer and are much more robust) but are more expensive. You may want an external hard drive (or an old hard drive with a usb lead as well for the other files). Use a free backup program such as Cobian Backup to automate this process especially if the files are in different places. Select the folders you want to copy and where you want to copy them too (seperate tasks recomended) and then click "run all tasks" to do a quick easy backup.