In most cases, HR will have already determined the pay rates. If you have created a new position, you will have had to work that out with HR before even posting the position. You can always try to use your management influence and change the rate of pay due to the expertise needed. Just make sure you have your boss’s blessing, and you have the budget to cover the change. Just be careful not to make waves with HR. You need them to be on your side. You will have years of heartache if you do not have a good relationship with HR…
If you are able to set the rate of pay yourself, check around and see what the competition pays. If you can pay the same, or even slightly more than your competition, the better the chance for a long-term happy employee. Look for the average rate of pay for the experience required in your city. It would also be a good idea to use some well-known companies rate of pay as a benchmark, even if it is nationwide. You want to find the range of the highs and lows. Hopefully you will at least be in the middle. Just remember, you get what you pay for.
If you have a range of pay for the position, you can try to balance it out by hiring the least experienced and not as technically skilled at the lower end of pay, and the more experienced with higher skills at the upper end of pay. However, if you do this, you need to stress to your employees to never discuss their rate of pay with their peers.