How do I print out a tree structure?

The trick is to pass a string as the indent and to treat the last child specially:

class Node
{    
   public void PrintPretty(string indent, bool last)
   {
       Console.Write(indent);
       if (last)
       {
           Console.Write("\\-");
           indent += "  ";
       }
       else
       {
           Console.Write("|-");
           indent += "| ";
       }
       Console.WriteLine(Name);

       for (int i = 0; i < Children.Count; i++)
           Children[i].PrintPretty(indent, i == Children.Count - 1);
   }
}

If called like this:

root.PrintPretty("", true);

will output in this style:

\-root
  \-child
    |-child
    \-child
      |-child
      |-child
      \-child
        |-child
        |-child
        | |-child
        | \-child
        |   |-child
        |   |-child
        |   |-child
        |   \-child
        |     \-child
        |       \-child
        \-child
          |-child
          |-child
          |-child
          | \-child
          \-child
            \-child