redandysafc,
If you are preparing youself to review and monitor the use of a vendor's procedure, you'll want to be very familiar with that particular procedure. It will specify minimum preheat and maximum interpass temps, maximum allowable heat input (if impact tested), qualified material thickness range, both min and max, and many other variables.
On the other hand, if you're developing a weld procedure for you company's use, on this material, metenger's suggestions will provide you with some basic information, but, there are many potential pitfalls and I would suggest you seek some professional advice.