I have a ASRock G41M-VS3 R2.0 motherboard and I want to buy a WD Blue 1TB SATA-III 64MB. Are the 2 pieces compatible and I can safely buy the hard disk or should I look for something else?
Yes the HDD is compatible with your motherboard.
SATA is backwards compatible, so the SATA III HDD will have no problems running on your SATA II motherboard ports.