RAID 0 is a way to set up two identical hard drives. The two hard drives work together as one hard drive. Whenever information needs to be written to it half of the information is written on one and half on the other. That way you theoretically half the time needed to write the information since you have two heads writing the information at the same time.
What I was talking about with the SSDs is that you install your operating system on that SSD and maybe one or two programs you use daily. Your music, movies, videos and other storage would go on your other hard drives.