You need a doctorate to become a Psychologist. This is generally about 10-12 of school total (4 for Bachelor's degree, 5-6 for Masters and PhD). However, you can become a licensed counselor with only a Master's degree (1-2 years after 4 years of college). This is a better route for most people who want to work with clients in a clinical setting.
SIMM is an acronym for single in-line memory module, a small circuit board that can hold a group of memory chips.
The DDR3 indicates the type of DRAM. SoDIMM indicates a small outline DIMM. (aka notebook form factor). For the other two (speed and voltage) check your manual. It will often state things like DDR-1066 where the 1066 stands for the speed the RAM can work at.