As for visiting Warsaw, IMHO the best place to stay is the Intercontinental, the best restaurants to sample the Polish cuisine are Warszawa Wschodnia and Smaki Warszawy, and a compact list of sightseeing tips can be found here: http://www.flyertalk.com/forum/europ...-warsaw-2.html.

Just like in Cracow you will be better off using public transport rather than driving a car unless you would like to go beyond the agglomeration.

If you have any questions or would like more recommendations, please let me know.