With the proliferation of cheap(er) disks and controllers, more of us are looking into setting up RAID on our Linux boxes. If you want to give it a go, but may not be familiar with it, this book may be a good bet for you. This is particularly so because of the current state of Linux RAID.
Linux RAID is a moving target right now. Both hardware and software RAID is available to us. Software RAID is probably more mature, so may likely be the safest bet. In any case, both options are fully explained, so you do have a choice.
What does RAID mean? I don't want to get into it, but the book addresses the issue of multiple meanings and a bit of history and definitions. While most of the explanations were adequate, I still couldn't wrap my head around the difference between RAID 1+0 and RAID 0+1, and why you would choose one over the other. (Actually, it's just me. I found a slightly better explanation in O'Reilly's Using SANs and NAS book. I know what they are saying, but I couldn't explain it to you. I just have trouble visualizing these two particular RAID methods.)
Also helpful are some planning and troubleshooting techniques, and some useful information on two available RAID management software packages, raidtools and mdadm. Information on choosing your filesystem(s)? That's all here, too.
I'm not using RAID on my Linux boxes, yet, but I expect my next one might. Because of the continuous changes in Linux RAID, I would expect an updated edition of this book to be offered in the not too distant future, but don't let that stop you from jumping in, now.