My son and I had the good fortune to visit there in June.
Mike is right, it has many tourists. It also has perhaps the most beautiful old city I have seen. For photography it wonderful to get a guide book and just wander the old city on the Danube's east side. On the west side of the Danube, you can see the Mala Strana (Prague Castle District) and the streets below. This area is also very crowded, yet you must see it.
Just ignore the tourists. You will have a good time there. You will find Pilsner Urquell nearly everywhere.
My son and I had a great meal at U medvidku pub and restaurant (Na Perstyne 7). They serve Budvar, which is nice (but not as nice as Pilsner Urquell), but they also have their own brew that is very, very nice (and also a little expensive).
You can take a Danube boat ride and photograph many wonderful buildings without so many tourists.
Have fun, Joe
