Prague’s airport is about 15 to 25 minutes outside the city, assuming you use a taxi.
On arrival you can get a taxi from the kerb of the arrivals area pretty easily. AAA Taxis are one of the more reliable companies and also offer an online booking system for the trip back to the airport, which will work out a lot cheaper than using a car from a hotel.
The airport itself is pretty nice, as airports go. If you’re a Sky Team elite member they have a “Sky Priority” lane through security which can easily save you about 20 minutes.
There’s a good choice of shops, bars and restaurants once you’re airside.
I didn’t get a chance to explore the business lounges so I can’t comment on them.
As airports go Prague is fine, and definitely not the worst place to spend a couple of hours while waiting for a flight.