I plan to purchase a new build soon, and it will be using a Samsung 830 64GB SSD (mostly for OS) and a Seagate ST500DM002 (for storage of files and majority of programs).
My question is: should I install my security software to the SSD? Would this help reduce the amount of lag the security software would cause on the computer? Or would it not make a difference where it is installed? And what programs, if any, should I install to the SSD for better perfomance overall?
Sure, the reads from the security software would be faster, just don't use overly bloated security packages like Norton. I would install your most heavily used programs on the ssd. Optimize the ssd, to reduce clutter and run faster as discussed HERE: disable indexing, move paging file elsewhere, and consider disabling system restore.