As the one guy said you could go to bleeping computer or similar site. I'm betting though you're more likely to get better computer advice here than running advice at bleeping computer.
It sounds like you may be trying to use the hard drives "easy to use" back up utility. You often have to install a program on your computer, follow some prompts and it will save an image, probably a proprietary image on your back up drive. As the other guy said copying may work best. Depending on how they are saved will determine the next move. If YOU created folders for your music, photo's, misc documents you should be able to just copy the whole folder to the bu drive. If they are saved in the default window folders, part of the library, it will require an extra couple of steps.
-Those library's are system folders and if you just click on my photos and copy, it will copy the folder, but not the contents.
-Open up the back up drive, right click, new/folder and name it "Dudes Photos" (without quotes) Go to where the pics are at, select all, copy, go to Dudes Photos, paste, wait, Done. Do the same thing, (make new folders) go to where you're other stuff is located and repeat. You can test this out my just copying one song or photo to the main folder of the new drive.
-Personally I delete all the S**t than came of the back up drive and treat it as a giant thumb drive. You can always download the "easy to use" software again.
I'm BIG on backing stuff up if you have more questions.