Researching pay rates HELP!

I was recently offered a promotion at work, it is taking on quite a bit more responsibility. Can anyone recommend a useful site so that I may negotiate my pay raise appropriately? I was offered a Resident Care Manager position. Please, this would be a big change for my family and we'd have to pay more in child care and more in gas as I'd have to commute 25miles each way 5 days a week instead of 3. I need to make sure that we don't just end up in the hole more. Thanks fellow nurses!
If I were you, I'd calculate the increased costs you would incur: gas, parking?, child care, etc. Add that total to your current salary, plus any increase that you may feel warranted by the increased responsibilities.I find most on-line salary calculators to be wildly off-base most of the time.