Hi everyone i am new to Linux, but i would like to know tons of information about it.
 

My first question is that! what is the major and minor differences between the new version (8) Fedora distribution of Linux to the version (5)?

Find and read the ChangeLog.

If you're going back 3 versions, that'd be changelogs; and good luck, it'll bore the *** off you :-)
Maybe you should explain why you'd want to do that?

The reason that i would like to know the difference between these two is because i have a project that i am doing on comparing Fedora version (8) to Fedora version (5; therefore, i like to know the difference between their features and their abilities.

If you can change the proj to be successive versions (eg 5 to 6, or 7 to 8) you'll save yourself a lot of grief.
It also depends how deep you want to go. If its a proj, I guess you'll want to go deep to make it a reasonable paper.