I will recommend these 2 books:
1) configuration and capacity planning by Brian Wong
2) Sun performance and Tuning (java and internet) by Adrian Cockcroft
If fighting against time, go to this:
, go to:
Guidelines for deploying EMC networked storage systems. Topics include configuration guidelines for optimizing reliability, scalability, capacity, and availability in various environments.
"EMC CLARiiON Fibre Channel Storage Fundamentals".
If still no time to read, but got lots of budget, do RAID 10 (Oracle says SAME, Stripe and Mirror Everywhere/Everything)
If this can't help, most likely no IO Storage Subsystem can help much. You will need application tuning.
Remember the 80/20 rule: 80% of the time, ONLY 20% of the data is still used.