This was writtne by Peter Ballinger last year, very helpful :
Arrival in Prague Airport
Upon clearing passport control, you will pass through some automatic frosted glass doors, leading you into the Entrance to the Airport.
To your left will be an automatic money exchange machine, to your right some stairs leading upwards. Infront, and to the right are car rental desks, public information desks, etc. It is from the public information desks that you can purchase 3 day (or even 5 day) public transport passes.
These give you access to buses, trams, and underground, and in 2002 they cost about 200 Kc for 3 days.
Exit the building via the front exit, and go straight ahead over 2 or 3 zebra crossings, following the signs for the 119 Bus.
After 100 yards or so, the roads conclude with a standard road, from where you can pick up the 119 Bus.
The 119 Bus runs from the airport to the underground stop at “Dejvicka”, and only to “Dejvicka”, i.e. it is the Airport Shuttle.
Once aboard the bus, stamp your 3 day passes in the on board ticket machines. This validates your tickets, and the 3 day period starts from the moment you stamp your tickets.
Dejvicka is where you can pick up the Underground (Green Line – Line A), and is about 3-4 miles journey on the bus from the airport. It takes about 15-20 minutes.
Just get off when everyone gets off. The bus goes no further than Dejvicka, apart from back to the Airport.
Being foreign, the bus will be on the correct side of the road for the Underground station.
Go into Dejvicka Station, watch out for the fast escalators as they are easy to fall down after a tiring journey especially when you are loaded up with cases. (There speaks the voice of experience )
Once in Dejvicka station, continue down to the platforms, the train will only be going in one direction from Dejvicka, and indeed arriving from one direction, as Dejvicka is the first stop on the line.
You will not need to stamp your tickets again at any time whilst in Prague, just look after them, and if a ordinary looking bloke (ie. No uniform) approaches you and shows you a “Sherrifs” Badge, he will be a ticket inspector, just show him your ticket and you’ll be OK.
Travel on the Underground from Dejvicka all the way through to the most appropriate station to your hotel / accomodation.
NB : I’d suggest either Mustek or Muzuem as both are reasonably close to Wencelas Square.
Getting to Stadion Marketa
My suggestion is that you take the Underground to Malostranska station (Green line).
Exit Malostranska station to street level, where you can pick up the No.22 tram towards Bila Hora which will take you up to the area of Prague called “Brevnov”. This is where the Speedway is.
The tram lines run in the middle of the road, accordingly the tram stops are in the middle also
You will need the No.22 that is going uphill, rather than the one going downhill back into town.
Once on the No.22, watch for the stops on the onboard displays, and the maps that are in the carriages. There are around 20 stops beofre you'll need to get off, but its a nice route up past the Castle. You need to get off at the stop "Vypich", rather than "Brevnov". You will see the stadium up on the hill from Brevnov, but Vypich is closer to the Stadion Marketa.