If aidren will allow me, I can answer your question.

You go to sleep mode normally by simply closing the eDGe up. To help guarantee it really does go to sleep, others have posted that pressing the Lock button on the Power Widget control before closing up the eDGe seems to make this reliable. On the Pocket eDGe, you can tell the eDGe is asleep if the green LED power light blinks once every 3 seconds.

When you open it back up, press the Menu button to wake it.

The eDGe has no fan. This was actually one key selling point for me when I first decided to buy it because I wanted to be on my night table to play music quietly to help me fall asleep and did not want a noisy fan keeping me awake