Ok, so recently I upgraded my Windows XP to the linux-based Kubuntu system, and I'm a little lost when it comes to figuring out some of the stuff that windows does automatically, like networking and getting multimedia support, but especially changing the permissions to files, folders and volumes... I just recently plugged my USB hard drive into my linux system, and although it let me view and utilize the contents of the drive, I can't write to it!
:confused: Any advice?

The linux kernel by default allows you to read an NTFS system. To be able to write to an NTFS system you'll need to enable that feature in the Kernel and recompile your kernel. It is experimental and can be dangerous as it could corrupt the file system. I'm guessing you have NTFS for your USB drive which is would explain this behavior.