How many days are you staying? Where are you staying? What's the focus of your trip?
For public transportation: don't bother with the 100 czc day pass, unless you plan a lot of on/off tram travel that day. There is a 18 czc for short trips on one tram/bus/subway and I think it was 32 czc for a 1.5 hour pass across multiple tram/buses. It is all done on the honor system, but its expensive if you get caught without a validated ticket (you validate it when you enter the subway system or on the bus/tram). You will be walking more than using transportation is my guess.
I have some restaurant names if you're interested, please PM me and I'll look them up later. I didn't get to visit them all, but they were the ones we were looking into and the Concierge recommended, one in particular I'm sorry I missed as it sounded wonderful. Czech love to eat/sit outside when the weather cooperates, you'll find a lot of outdoor eating places. Avoid anyplace that offers you a euro priced menu, it is a tourist trap and very likely overpriced.
If you're there for long enough and are interested, there is an outlet mall I can offer information on at the Depo Hostiva (sp?) stop, its the last stop of the line with a free shuttle to the mall. It wasn't huge, but not too bad for an afternoon excursion. There is another location I was told about for good shopping (outside the tourist area) which I have noted somewhere if you're interested.
Last ... on Celetna (behind the republiky namesti metro stop), give one of the Thai Massage places a shot if you like that. I am sorry I didn't stop by sooner, but when I did I felt like I was back in Thailand. Just excellent after a day walking around. Entrances are suspect, but definitely worth it (and inexpensive). All the places take appointments, as well as walk in when there is an opening in the schedule.
You might want to peek at the Prague Do thread in CommunityBuzz, as they had discussions on what to do/see, with lots of q&a. Also, they had a car service that most everyone used which they liked.
It's a beautiful city, enjoy!