according to The gal at the hotel where we will be staying says the bus would be difficult and a private driver is about $140 so we may try and rent a car for the day if that is possible.

I would recommend spending 4 days there, especially if you are interested in WWII history.

Schindler's Factory is incredible; I was blown away at how in depth it was and plan to spend a few hours there. Auschwitz was also really a learning experience as well.

When we went to the salt mines, we didn't need reservation at all. We got there, i believe, when it opened and waited about 10 minutes. It is really easy to get to by bus.

If you are interested in Communist history, I'd recommend checking out the area of Nowa Huta. It was originally supposed to be Stalin's model communist city and it has the Solidarity Monument and the former Lenin Steel Factory. I know some companies do tours over there.It is somewhat far from the city centre.

I also recommend trying a milk bar (basically a Polish canteen/stolovaya). Pod Temidą is where I went.