Do - Consider your motherboard's RAID chipset. Most on-board RAID is designed for redundancy, not performance. If you want RAID0 or RAID1 benefits, seriously consider getting a performance RAID card with a RAM cache (see Adaptec's 5405 card). In any case, test different configurations with benchmarking software before installing all your apps.
Do - utilize a backup system like Norton Ghost to make regular backups of your OS. SSDs, should they fail, tend to fail without warning.
Don't - use any defragmentation software on your SSD drives. Wear-leveling makes this ineffective and wasteful.
Don't - store photos, music, multimedia on the SSDs. Why waste performance SSD storage on static data, unless absolutely critical, when there is cheaper, higher capacity secondary storage available (e.g. external or internal HDDs)?
Recommendation - for the ultimate in OS performance, make room in your budget for something like Gigabyte's iRAM drive or HyperOS's HyperDrive to store your pagefile, TEMP folder, and Temporary Internet Files on. You'd only need 4-8 GB of Ramdisk storage for this purpose (depending on how much physical RAM you have). This DDR-based storage makes your system FLY, and this type of data is not critical enough to warrant backup/redundancy (but enough to cause a performance hit in any other configuration).
These pointers are based on my personal experience with all the hardware I mention, and others.