template syntax for nested classes - custom iterators

I am trying to implement a generic tree class, as I had mentioned in a
previous post. I want it to be STL like, so I went and researched how
to implement an iterator and copied an example from a page online.

template <class T>
class GenericTree
{
private:

   class Node
   {
   public:
      Node(const T & data) {}

      // other methods
   };

   Node * m_root;

public:

   // Other methods

   class Iterator : std::iterator<std::foward_iterator_tag, T>
   {
   public:

      Iterator(Node * node)
         :
         m_node(node)
         {}

      // Other methods

      T * operator -> ()
      {
         return (&*(GenericTree<T>::Iterator)*this);
      }

   private:

      Node * m_node;
   };

   Iterator begin()
   {
      return Iterator(m_root);
   }

   // Other methods
};

When I use it with the following code:

GenericTree<int> tree;
GenericTree<int> Iterator it = tree.begin();
it->() = new int(0);

I get an error:

"expected unqualified-id before '(' token
In member function 'T* GenericTree<T>::Iterator::operator->() [with T
= int]'
Instantiated from here
dependant-name ' GenericTree<T>::Iterator' is a parsed non-type, but
instantiation yields a type
note: say 'typename GenericTree<T>::Iterator' is a type is meant

I assume I need to use the typename keyword somewhere, but am unclear
where. Is my syntax incorrect? Can someone give a correct syntax with
nested template classes?