Procedure for External Hard Drives on Entering Sleep

Hi Mac Users,

I've just gotten a MacBook Pro 15-inch w/ Retina (2.3 GHz, 256 GB SSD, 16 GB) and am amazed at its superiority over the Windows experience. But there's a lot for me to learn. I have some questions about its use.

Some background: I have an external USB 2.0 1/2 GB hard drive that failed on my windows machine (corrupt FAT). I reformatted it for OS X and was using it for time machine backups. A couple of times I put the Mac to sleep without un-mounting the drive. When booting up again, there was a message warning about shutting down - drag the hard drive icon to trash. Well I forgot and made the same error. Now neither the Mac or the Windows machine will recognize the drive. So it's probably toast.

My questions:

• Is there some way to automate the shut down process when going into sleep mode to avoid external hard drive problems?
• Is there some way to have OS at least warn me about the need to dis-mount the drive when I'm entering sleep mode?
• What is the normal process with external drives when shutting down or entering sleep mode?

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Best Regards,
Russ