As others may mention, I've written about several of my astral experiences in my blog
But to answer your questions briefly...
I sort of stretch out of my body and then when I look back I can see the shell/body lying on my bed.
yes it really feels THAT REAL. It feels more real than when you're encased in the body. Your consciousness is free. It's an amazing and unique feeling that I wish everyone could feel at least once.
We've had some discussions in this forum about how to achieve astral states. Read through the old threads and see if they help. Learning lucid dreaming is a good first step.