It is easy to get to Prague from any place in Europe. From London, you can take any of the numerous direct flights to Czech Republic or even take a train. You would have to change a few times along the way, for example in Paris or Berlin, and it would take you much longer to get to Prague than by plane but it will definitely allow you to do some sightseeing from the train.
Accommodation in Prague
Prague is full of tourists for around 6 months a year. Therefore it is best to come to Prague off season between October and March, when the prices of hostels and hotels go down and you are more likely to find cheap apartments in Prague. But even in season you can find accommodation for every budget in form of the university dorms. Of course, when choosing dorms you cannot expect high standards of accommodation but the price is worth a little hustle.
Public transport in Prague
The best way to explore Prague is on foot and there are a lot of alleys especially made just for pedestrians. However, sometimes to save time and effort (since Prague is mostly situated on the hills and require a certain level of fitness to walk through the city) you can use a well-developed public transport. Four lines of Prague metro allow you to quickly get from one place to another. You can also choose trams of a bus ride through the winding streets which will allow you to admire the beautiful streets of Prague. You can also use taxis but the drivers are known to stretch foreign tourists. If you get a taxi, make sure to agree on the price before you enter the vehicle.
Czech cuisine has many fans. While in Prague, it is necessary to go to a real tavern. You might not find it in the city centre but if you around Karlovy Namesti (New Town) and further towards Visegrad, you will find a lot of non-tourists pubs, where the prices are much lower. For a good and cheap meal head to the Zizkov and Vinohrady districts.
Sightseeing in Prague
Prague offers thousands of interesting places to see. These include the historic squares, churches, numerous themed museums and amazing streets, scenic places in the hills and cool bars. If you plan to have an intense tour of museums and galleries you can take advantage of discounts (quiet modest, usually around 10-20 percent). If you want to see private museums you can buy a tourist card for 1000 crowns (valid for 4 days).