Good luck!! The program Lucky rec'd IS good with the added benefit of being shareware. I find Paint Shop Pro to be just as effective. Equally good - for my needs anyway - is this free program called Photo Plus
Under its Color and Input/Output Options , you can change the resolution.
I hope this all helps. It took me ages to get photo resizing and edting down pat - and most of the time, it still only works when I am lucky. The 1st photos of YY I uploaded were hazy and not great - taken with a digital camera so I could only blame the photographer (me) and not the software of the image editor.