RAID 0 has nothing really to do with SSD's (although I guess you could have multiple SSD's in a RAID 0 configuration).
RAID 0 is when you take multiple identical HDD's (or SSD's) and treat them as 1 complete HDD that has a capacity that is the sum of the HDD's. This increases performance since now the multiple HDD's can function in parallel thus increasing the bandwidth. More drives in the array means higher bandwidth, but greater risk of data loss. The problem with this is that if one drive fails all the data is lost because the effective drive requires all the drives to function as a whole. There are ways around this by introducing other RAID configurations into the mix which can create redundancies, mirroring or parity for error correction and recovery.
RAID 0 is useless for SSD because usually higher capacity SSD's will perform better than 2 smaller SSD's in a RAID 0 configuration. You are better off buying a 128GB SSD then two 64GB SSD's and configuring them in RAID 0. For HDD's this is a different story. The only useful form of RAID when it comes to SSD's would be something like RAID 1 where identical data is written simultaneously two to drives. If one fails, you still have access to all the data since it was an exact copy.
Check out more about RAID at the following link:
http://en.wikipedia.org/wiki/RAID#Standard_levels
With just 1 SSD and 1HDD I wouldn't worry about RAID. With a 64GB SSD the best option is to use Intel SRT in which case the OS will only see one disk which is the HDD.