Okay well for started setting up a SSD boot is amazing, and a good choice, I do NOT recommend it for games though as it will have no noticeable impact on performance.
For the SSD I reccommend around a 32gb or 60gb and this will be specifically dedicated to your boot ensuring boot times of 3-15 seconds after post. Install your new SSD into your computer, Put it into a sata port 0. Disconnect your harddrive for the time being, and insert your Operating system CD into the computer now bot up and install your OS onto the SSD as if it were a new computer. after it has been installed, turn off your PC and recconect your harddrive to "SATA 1" and the SSD to "SATA 0", in the bios change boot priority to always boot from the SSD, After your computer is up and running you need to remove the old operating system from your HDD, ONly use your SSD for Antivirus, Program Files, and Drivers/updates. The HDD should be used for any other applications such as games. After all of this is done you will boot back up your computer, it will boot from the SSD leading to what looks to be a fresh computer install. Open computer and make sure the SSD is C:, if not rename it to C: and the HDD to D:, from there you will be able to access all of your files and games on D(HDD) while still having the SSD handling any system information and shutdowns/bootups.