Hi I can recommend the Regent in the old Jewish Quarter tho it is so nice and cheap its hard to get booked there. Check out Tripadvisor for others. I too would recommend the Salt Mines, about 400 steps down to the bottom on a wooden stairs but its grand. Not claustrophobic when you get down as the roofs are quite high and the passages, generally wide. It does however take 21/2 to 3 hours for the tour but as ShaneMc says, it well worth a visit. Most of the buildings, especially around the castle, are good for photographers.
Check out the Cathedral domes and the Castle courtyard - I got some great photos there in the snow last Dec. Also the Jewish quarter, Kazmierz -spelling probably wrong- but it has great old world atmosphere and hardly changed much in the last 50 years or so it seems.Old shops abound there like what you would have found here decades ago. People are lovely and helpful, fair amount of younger ones with good English, food cheap, drink very cheap, easy city to get around. Tourist office in old tower building on Old Square very helpful, will advise you about cheapest way to take trip to salt mines, etc. Private minibuses we took cost 2.5 zloty each way and 40 zloty for the entrance to mine itself and guided tour. A little extra to take a camera in. Can't say one bad thing about Krakow except it rained a lot during our visit but sure we are well used to take? Oh and we liked it so much we return for another visit in March!