RAID isn't a proper backup solution.
If you delete something by accident, it'll get deleted from the other drive in the array as well and your file is gone forever. There are horror stories about sites which used to use this technique and are now completely offline after a kernel bug wiped a drive which then of course wiped the other drives. RAID has its uses but reliable backup isn't one of them. Worse, if your computer blows up, all drives in the array are probably useless.
I use a Mac at home so can't offer any Windows based solutions, I'm afraid. For Mac, I use Carbon Copy Cloner to clone my main drive in it's entirety. I can boot from this backup drive just as if it was my main. I also have another backup drive which doesn't stay in the computer and I do the same backup to this drive but less often and keep it hidden in my bedroom.
Ideally, you want to keep an off-site backup in a friend or family members house as well. If (heaven forbid) your house burns down and all your backup drives are in your office, all your backups are gone as well. An off-site backup will mean your data is protected from a fire or theft in your house. This is something I'm looking to start doing soon.
The main part of any backup is testing. You might say you backup all your data, but have you ever tested restoring from backup? Remove your main drive and imagine it's completely shot to hell and unusable. Then try restoring from your backups. If you can't restore, your backup process is useless.
Look at finding a program which will allow you to completely clone a hard drive. Do frequent backups, and test regularly as well. If you have to pay for software, then pay. Don't be cheap! What price would you put on tens of thousands of your photos which you can never get again?
George.
