Workflow and automatic transitions

Hi,

I have almost completed my workflow, only one tiny piece is missing.

My workflow have three stages; Edit, Review and Publish.

I don't want normal users to see the workflow tab, but I want to set an action when the author saves it in Edit or Review stage. What I can't figure out is how to automatically move a node from Edit stage to Review and in Review send a new email should be sent out when the author saves it.

When a new node is created this is easy as it will automatically be moved to Edit and thus fire that trigger. But when a moderator moves it back from Review to Edit there are no triggers for when it is then updated and saved by the author.