all parts are good. the PC im using now was my first build too all you need to take into account is your budget and getting best out of it so consider this for gaming you need to spend a good amonut on the vid card or the processor you could argues both i guess
since RAM is fairly cheap i havnt got much to say about it apart from checking reviews as they isnt much difference. for $600 you should stay away from ssd's you can pick up 2tb HDD's for fairly cheap too.
for Power supplies you can generally get away with a 650W or a 850W atleast between those since you probably wont OC and you wont be doing SLI
As far as building the actual thing just imagine it like lego for adults after a while you will be able to strip it down with in minuites.
This would be a good solution. But CPU is an overkill for this GPU you could save a little there and get a slightly better GPU. like aMD R7 265 at 140 $ or R9 270 at 180$ or R9 270X at 200 $ in this price rnage, NVIDIA is comletely outclassed by AMD since they lower the price of their card cause mining lost in popularity. There is the NVIDIA GTX 660 which is between R9 270 et R 270X in performance but at 200$
CPU is an overkill for a 750 ti Yes, best solution is when your cpu is on limit to be bottlenecking your system so you get the most you can get from it. a 120$ CPU would do just fine with every of these cards.