Whether you’re looking for practical, hands-on technical information or a good introduction to well-established enterprise system architectures and frameworks, the IBM Redbook site has much to offer. IBM “redbooks” provide very good tutorials and “how to” guides.
As an example, there is a good overview of Storage Area Networks in Redbook SG24-5470.
You can download it as a pdf file.
You will see a page in which you can enter your business contact information (if you choose to do so). If you’d rather not, scroll down to where it says “I don’t want to provide any information at this time.”
There’s plenty of useful and interesting documentation on the redbook site. Check it out sometime.