i put in ram in my macbook pro. yay me. upgraded from 4gb to 8gb... idk why the heck a brand new system that came out in early 2011 still has only 4gb of ram, thats rediculous. if i had one complaint about mac, they could have went for two 4gb sticks instead of cheaping out and throwing in 2 2gb sticks. jerks lol
Well, Apple was always good at marketing average hardware and selling it to you at a premium. No wonder OS X is cheap considering the price at which they sell you their hardware. Just take a look at their margins, i'll give them points for marketing and user interface, but that's about the only thing where i'll give them points.
you'll be fine. take extra care with your CPU. make sure you get a good thermal paste and apply it properly...the GPU won't give you any issues as long as you have a case that can hold it.
Yep, it'll probably take 1-2hours since it's your first time. For the thermal paste, get one from a reputable brand like Artic Silver 5, Arctic Cooling MX-2/MX-4, Innovation Cooling Diamond, etc. Any of those has only minimal differences in performance and will ensure good heat transfer given good paste application. You'll find every tech/regular here has his favorite paste, any of those should do the trick.