Depending on your background go to a used book store and thumb thru thermodynamics texts. All should have power plant cycle discussions.
If you are thinking of a specific area, then that is another question.
There are several engineering software packages that will perform an iterative heat balance and generate a heat balance diagram for various plant conditions.
If you are only going to perform a single heat balance for a single plant, I suggest that you pay to have a specialist perform the balance...
The "old horse" that has been around a long time is "PEPSE"