Many times people need one solution for using Tree structure on thier VF page. There are many solution using JS/JQuery. Here i used jquery treeview plugin and created one apex component which can be used directly in you VF page. You simply need to use following syntax to embed this tree in your VF page:

Here is a working demo for this SF Tree.
http://labsprojects-developer-edition.ap1.force.com/sftreedemo

The component provides two JS method on click of parent and child node and send id of the node. You can define those methods in our VF page and do process whatever you need.