Sounds like you are off to an excellent start!
I normally try to start by picking a powder that has a fill % I am targeting and is knows as an accurate powder for my caliber (the Nosler reloading manual can be an excellent resource as it shows % fill, and lists powders by burn rate).
If you haven't checked out the Dan Newberry OCW
it is a very good process to guide your load development. It sounds like you are asking what your process should be.