[bend the light]

I sometimes have problems with noisy images, and I can't quite get to the bottom of it. So, this is what I might do with a typical picture...where might noise be creeping in...where might I be better doing something else?

Shoot at ISO 100 wherever possible, try to have good light.
Copy RAW files into Bridge...sort through good and bad, and delete the bad.
Open an image in Adobe RAW...
Check for burnt out, or blocked up blacks on the histogram...adjust exposure, recovery if burnt out, slight increase in clarity. Tend to leave all other bits alone...
Open image in Photoshop.
May do a curves adjustment (on adjustment layer) if necessary, nothing fancy...S-curve mainly. May adjust saturation (again, on adjustment layer).
Usually add sharpening with unsharp mask, typically radius is around 1 max. Slide up until it looks ok, but not oversharp.
Crop to 10in x 8in x 300ppi.
Save as PSC and then as JPEG, quality 12.

Anyhting in there a problem, you think?
I wonder about cropping...if I crop to 10in x 8in 300ppi, am I adding pixels, or deleting some? If I crop with nothing in the size boxes I will get non-standard crop sizes, but will I then not be extrapolating pixels, or something?

I welcome all ideas to avoid noise in PP.

Thanks