Time Machine help

Ok guys I have some questions with time machine and my first time using it. I have a 320 gb external hard drive. I have a few files on there such as pics and songs. I'm going to move those folders over to another external hard drive. I think after I do that I'm going to set this drive up as time machine with my mac. Now do I have to do these steps first?

1. Launch Disk utility
2. Click on the drive in the Left hand pane of Disk utility
(MAKE SURE YOU HAVE THE CORRECT DISK)
3. Click on the partition tab
3. Click on Options
4. Select GUID format
5. Click Apply
6. Click on the Erase Tab
7. Set the VOlume FOrmat to Mac OS Extended (Journaled)
8. Click Erase
9. The volume should show up on your desktop now.

Or does time machine erase everything on my drive when I set it up first. Also when I set up time machine on this drive I plan to move back the orginal files I had on there back to this drive so I can have 2 backups. So is this all correct??? Thanks.

 

So are you saying just use the external for time machine and nothing else??? I think I'm just going to do time machine once because I don't have much stuff or do a lot on this machine anyway. Also the files I have I thought I could just drag them over and not even do a partion. They should all be in seperate folders.

 

So how about I just use the external drive once for time machine just so I could have a backup. Will that work where I can drag other folders to the external drive and use it as extra storage??