Okay, so you want to transfer the files to her computer. Then get the flash drive thing I was talking about. Any store that sells blank DVDs or CDs will have flash drives of varying sizes. They are simple to use. You plug the drive into your computer and it will install itself. You'll then see it pop up or can go to "My Computer" and see it listed beneath your main hard drive. You just drag and drop or copy and paste the files you want to transfer to the USB drive, take it to the other computer, and copy them from the drive to her computer. It saves time (copying to the flash drive is faster than burning a disc) and requires no special program to burn the disks. You then don't need to worry about the type of disk, for all flash drives are the same in this respect.
If you are dead-set on the disc thing find DVD-R. They are standard DVDs and will be readable in most any DVD drive. You can only write to them once (unlike the flash drive or DVD-RWs) but I can't recommend DVD-RWs because they have a tendency to fail randomly in my experience.