When you boot from an SSD you don't strictly need any other hard drives. However, SSDs are expensive, so people often get a small SSD like you've chosen and larger drive(s) for mass storage of things like music, video, and pictures. I'm not really sure what your logic is behind getting one black and one green drive. You might be better off with a 120gb SSD and one 2TB HDD. 120gb is big enough to install several programs, but you can always put programs on the HDD as well.
In terms of installation, the only thing that needs installed is your OS which will probably go on the SSD. You will also want to format the HDD(s). (HDDs should be full formatted the first time and then quick formatted after that. SSDs should never be full formatted.)