If you have free electricity or free power source mining for you is profitable and it depends on what mining machine you have because if you mine coins with GPU the ROI will take years before you reach the ROI. But if you are mining with ASIC miner I think you can reach the ROI fast.

You don't need a deep knowledge of Hardware/software. It is enough if you know how to maintain your miners or how to clean them and knowledge to set up the pool is enough.