you using photoshop? (i assume so cos of the psd files...)
I'm sure people will have their own preferred methods and quality required (and porbably better methods!) but this works for me:
If i'm going to put an image on my galleries, I save the 16bit TIFF to keep it safe then resize it in photoshop to 800 x 600 and convert to 8 bit and sRBG profile. Then save it as a JPEG. Then i stick it into Image Ready and do 'Save Optimized As' and it goes from (initially) a 46Mb TIFF to about a 150Kb JPEG! Quality is fine for my purposes. Yeah OK it's not as fine detailed as the original but people do need to be able to view it easily!
HTH
Dave