RAID 1 rarely saves the day. Read http://forums.cnet.com/5208-6121_102-0.html?threadID=408753&tag=forums06;forum-threads
Not only that, the usual documentation fails us when we need to recover from a failure.
I'm planning on building my own computer at some point in the near future. I wanted to set up the system with a 40 Gb SSD as the drive with the OS and some main programs(games, frequently used, etc.) and two 1.5Tb HDD in Raid 1. Is this a hard set up? How do I do it?