I want to see Warsaw but really have no clear idea on what there is to see and do there,and the same applies to Krakow.
I believe that these cities were all but destroyed in WW2 and have been rebuilt.
The sad sights of that conflict have no appeal for me,so ,what`s to do on a more joyous note? Food ,museums etc? How many days in each city?
Budapest is pretty easy as I`m aiming to perhaps take day trips on the river,Is 2-3 days enough?
What else would you recommend?
I`ll be there in early spring.

Quick peak at Wikipedia shows that Old Town Krakow is a World Heritage site, so sounds like well worth a visit. We loved our week in Budapest, 2-3 days would get you the highlights I suppose. I'd suggest visiting the Parliament building and Buda Var and a cruise on the Danube. They have some great museums, too. We loved walking or taking the tram to see the different neighborhoods, especially Margaret Island.

Warsaw's old town is reconstructed; Krakow's was not destroyed. Investing in a good guide book (or two) should give you a good start.

You are correct in the understanding that Warsaw was absolutely leveled in WWII and the historical old town is a complete rebuild. Krakow, however, was was hardly damaged and it's central core is a marvel.

To my unexpected delight (sorry for doubting you Poland!) I found the food in Krakow to be marvelous as well. Never mind the sublime pierogies, what those folks can do with some mushrooms is mind blowing. And the Krakowian version "Zurek" - a fermented barley based soup with smoked sausage and a quails egg or two in there in the hollowed out bread bowl - still makes me swoon. I will take humble peasant food that has been mastered by the collective efforts of generations of people through the centuries over haute cuisine any day.

I found Warsaw disappointing but loved Krakow (although I gather it is much more crowded these days). Budapest deserves plenty of time - click on my name for my Hungary TR. But obviously you need a guidebook or two.

Thanks for the excellent advice,I`ll try 2 full days in both Polish cities and 4-5 in Budapest.
The food sounds terrific,though being a fish eating vegetarian might prove a bit of a challenge?
I`m thinking of a self catering apartment in Budapest or are hotels my best bet?