I have a huge collection of 6x6 negatives and slides, most of them outdated product shots; I discarded hundreds, but in between were shots of studio setups and people on site which I liked to keep.
I placed negatives and slides on a cheap lightbox and photographed them with a canon A1200 in macro mode - a really low-end point-and-shoot, but the results were surprisingly acceptable.
The autofocus went nuts, so I used a simple clamp fixture to keep the camera in position and shot about 250 repros. Not High-end, but it did the job in "no" time.
If you have no ligtbox, a pane of glass from a picture frame with a sheet of semi-transparent paper will do.
For "post-processing", Picasa did a very decent job.