I have a question/problem with the display of my stories on kindle.

All the stories I have on it are mobi files (changed PDF files since I read almost only fanfiction on my kindle). The problem with these mobi files are that on my kindle, they have a white background and underneath is only the name "Personal". Not the name of the story itself or any picture that I know which file it is.
How can I change that? Because if you have so many files on your kindle, it soon is so confusing since there is no name to identify them. It's frustrating.
I want the story with a picture and a name. Does anybody knows how to do that?
On my PC, when the kindle is attached, I can read all the names of the stories but not on my kindle index.
HELP!

If you go into preferences/output options/mobi output, make sure the box marked "enable sharing of book content via facebook etc is checked. You will have to run a conversion (mobi to mobi) again, then reload to your kindle but the cover will now show up.

where do I find preferences/output options/mobi output?
In the settings of my kindle or on my pc?

If you go into preferences/output options/mobi output, make sure the box marked "enable sharing of book content via facebook etc is checked. You will have to run a conversion (mobi to mobi) again, then reload to your kindle but the cover will now show up.

I have found it now. But my new question is now, the Amazon whispersync. Does it mean since I have marked the box, my kindle wont save the position I am reading anymore?

It saves to mine but if I won't sync if I switch reading between Kindle and K4PC.

Thank you sooooo much hun. You helped me out.   

It will sync among your devices if you email the mobi file to your device as a personal document.  That file will be treated as a regular Kindle books and will sync among devices and your highlights saved on the Cloud.  However, you have to have the newest (or second newest) Kindle software update.  Good luck.