Need some help with my pics please

[G10]

I have started putting together a site and am struggling with the quality of the pics on it: http://www.doseuk.com/newjuicysmile/index.html

I am no graphic designer as you can see (leave the smart comments till later eh ) and would like the pictures clearer without comprimising the the loadup time.

I think it's already a tad on the slow side if people were hitting it with a 56k.

I have messed about with the pics within photoshop and have the psd files aside but there is a fine line between loadup time and quality pics and I am struggling with it.

Any ideas would be a great help.