I know that it passes the recommended power rating of 500w, but do all of the other technical things about the PSU (rails etc? I have no idea what these are, something to do with the current of each rail???) meet the requirements?
I am a complete noob when it comes to PSUs, so please help me out
The Cooler Master GX Series 650W (RS-650-ACAA-E3), shown in that link you provided, is the discontinued model made by Seventeam. It's been replaced by the RS-650-ACAA-D3 model made by Enhance Electronics which is 80 PLUS Bronze certified.
Both models have a +12 Volt continuous current rating of 52 Amps and come with two 6+2 pin PCI Express supplementary power connectors.
The GeForce GTX 560 Ti should have a power supply with a +12 Volt continuous current rating of 30 Amps or greater and have at least two 6-pin PCI Express supplementary power connectors.
The Cooler Master GX Series 650W is more than enough to power your system with that graphics card.
Not all Cooler Master PSUs are good. The Extreme Power Plus Series and Elite Power Series PSUs are utter garbage and should be avoided at all cost.
I'd just get a quality and well built corsair or seasonic psu, i would never buy anything else or recommend to my mates. in 10 years of pc's and plenty of corsair psu's fitted to friends, never had a problem in any of them some still going years later.
It's just not worth getting cheap psu's, as in 1 second alot of money down the drain if psu fails