public function edit($clientID)
{
    // get the clientsite
    $ClientSite = clientSite::find($clientID);

return View::make('edit')->with('ClientSites', $ClientSite);


}

     public function doEdit()
     {
         $ClientSite = clientSite::findOrFail(Input::get('clientID'));
        $ClientSite->siteName = Input::get('siteName');
        $ClientSite->description = Input::get('description');

        $ClientSite->save();

        return Redirect::action('PagesController@home');
    dd($clientSites);    
     }

}

you have dd($clientSites); the wrong place. Move it up to you edit function.

like

     public function edit($clientID)
{
    // get the clientsite
    $ClientSite = clientSite::find($clientID);
     dd($ClientSite);
     return View::make('edit')->with('ClientSites', $ClientSite);


}

I know you said you're new this "this framework" but this is basic PHP debugging.

@webdevdea dd() will var_dump() the variable and die()

i think your machine is case sensitive. I encountered before where my production server is case sensitive. :|