Help on: Redefinition of class, but the only definition

Ive split the class into a seperate .h and .ccp for the implementation of things.
I have the class definition in the .h and thats the only time I use the key word **[COLOR=Blue]class [/COLOR]**as Im obviously creating a class.
I coded these originally in notepad (lol), but since have run it through Dev-C++ (4.9.9.2). I fixed a majority of the errors that were bound to be in it, however I have this error that it keeps throwing at me during build-time saying:

[COLOR=DarkRed][FONT=Courier New]line 13: redefintion of 'class Details'[/FONT][/COLOR]

then below that error it has:

[COLOR=DarkRed][FONT=Courier New]line 13: previous definition of 'class Details'[/FONT][/COLOR]

as you can see… the apparent redefinition is actually the original definition of the class. It also happens to be the only definition… Can anyone explain whats going on here?

If possible, can I get clarification on how to properly include the seperate .h and .ccp files and which files need [COLOR=Blue]#include[/COLOR] statements and the [COLOR=Blue]#ifndef[/COLOR] statements, as I dont think Im 100% on what should be where.

Thanks guys.