|The best method to address that issue is to separate the OS from your programs, as you are doing and go one step further and separate the personal files on a third partition.|
Then use an imaging/ backup program to create an image of each partition separately. Doing things that way allows you to restore from and image without affecting the other partitions.
Each partition will need to be reimaged at different intervals. You can do that easier and faster than if you did the entire drive at once.
Your person files don't really need to be imaged at all. Just backed up. Imaging usually involves compression of the files to save space. You aren't going to compress MP3, jpg, etc much more than they already are.
There are some free imaging/backup programs but the commercial have more features and are somewhat easier to use. Acronis True image allows you to perform incremental backups. This means it only backs up the changes you made to the partition since the last back up. Ghost is also good but if I were buying now I would get a version of Acronis. Below are links to their site plus a good vendor to buy from at discount. Read about the products and what OSes are supported and then decide what you need.
One last point to mention. These programs can write to pretty much any media available. IMO DVDR is the preferred media. You can boot directly to the DVDR and perform the restore. The media is cheap. Multiple copies can be made for cheap. No risk of mechanical or electrical failure like with drives.