well i dont have time to critique every single element of the build but i can offer some ideas....
• Intel Core i5 2500k Quad Core
--- not a bad choice but i would get an i7 myself.
• Asrock H61M-VS Motherboard
--- just make sure that you check compatabilities with ram, cpu, etcetera.
• 8GB Corsair Vengeance single module
--- single module? BAD IDEA. let me repeat that. BAD IDEA. if the motherboard is dual channel then use 2x4gb or 4x2gb modules. if the motherboard is triple channel use 3x2gb, 6x2gb or 3x4gb modules. if you dont you will lose any performance increases the multi-channel ram provides. not to mention any other issues which may arise.
• Integrated Sound Card
--- should be fine, just make sure it has the ports you want. personally i like making sure it is of a higher quality but your choice.
• Corsair Hydro H80 High-Performance Liquid CPU Cooler
--- why? dont waste your money. if you aren't overclocking (yet) the stock cooler is fine.
• DVD+/- RW - 22X Samsung SATA
--- standard fare.. no problems here.
• 500GB SATA Hard Drive SATA 3
--- for the fastest performance getting a 60gb boot drive and a hdd for backup is ideal and within budget. keep in mind that the drive could even be sata II as hdd's cannot exceed the data transfer limit of sataII. with ssd drives there *might* be a benefit of sataIII depending on the particular model.
• Nvidia GTX560Ti 1024MB
--- not sure of the actual model here but sounds alright. check the toms hardware charts to see where it ranks in fps wise with the games you want to play. i would suggest buying evga as they have an upgrade program. and they come with alot of accessories.
• CiT Jupiter Midi Tower Gaming Case Blue LED Fan No PSU
--- not familiar with this case. what i can say is to make sure you have a case with at least 2, preferably 4 120mm fan slots. i would avoid fancy led fans but this is your choice. make sure the layout is good for airflow.
• CiT 500W Black Edition PSU
--- not familiar with the CiT brand. make sure you do your research on this one. the psu is not an area where it would be wise to cheap out. you can probably do this on 500w but you might want to give yourself a little more headroom, say 650 or 700w. my older system with an i7 and gtx470 can draw just about 500w under decent load. i'm using a 1kw psu for plenty of overhead. you will also want to TRIPLE CHECK that the model has all of the different power connections you may need. specifically the main power cable, aux motherboard power connectors and the six pin connectors for your video card.
• Windows 7 Home premium 64 bit
---home premium works fine. suggest OEM copy as it is a good bit cheaper.