Its best to back up to an external HD, another internal HD, or another computer on the network. This way if your HD fails you have the data which was most recently backed up.
Easiest manual method is to back up your User account named folder which contains all of the subfolders Documents, PIctures, etc. I prefer to back up only the active User account sub-folders since I know which ones are active and being used. Simply drag the folder(s) to the backup drive.
To import the backed up data, open the given folder, on Organize tab choose Select All, drag the group to the corresponding folder under User name on the lefthand Explorer bar, don't release the left click until Explorer stops unfolding and it confirms which folder is being copied into, then drop the files there.
What is it that you need to do now exactly so we can help you further?