I think you just use the TreeNode object's FullPath property and it gives you the path from the root to the node. For example, "root\branch\leaf."
To list the children of the root, you'll need to iterate through its Nodes collection. If you want to enumerate all of the tree's nodes, you can do that recursively. I.e. make a routine that enumerates a node and then calls itself for each of that node's children.