A lot of times, a hard drive crash is simply the loss of the boot sector. A good computer technician has tools that can recover lost files, provided you haven't reformatted the drive.
As for backing up. There are dozens of memory storage devices on the market now, and prices are still going down.
I will load my memory card to my hard drive in the my pictures area. I then immediately copy that entire new folder to a network drive. Once I have enough new photos on the network drive to fill a DVD, I will burn a new DVD for storage elsewhere (at work in my case).
Editing done to a photo (lightroom or photoshop) are always done to a copy of the original. The copy always gets the original filename with a -A or -B added to the filename. (12345.jpg is the original, and 12345-A.jpg as the copy).
Filename structure is whatever suits you best. I always use Date+CameraFilename. The folder has date and subject description.
My daughter, on the other hand fills a memory card in the computer, and then buys a new card. She has no clue how to use a computer even though I've shown her (and her husband) many times. She will take a 1G memory card to the photo lab, and view all the photos using their kiosk, and selecting her favorites to get printed. She counts on me taking her extra memory cards and loading them onto my computer for safekeeping. NOT a good plan, but it works for her.
Finally, remember that NO backup plan is foolproof. The most difficult part is forcing yourself to do the extra steps.
I hope this info is clear to you, and I'm sure you'll get other suggestions that are probably better.