Bus
OK, we’ve only lived in London for 30 years, but we throw our hands up in confusion when it comes to finding a bus at Waterloo. Partly it’s because there are so many.
If you look opposite platform 5 (or so) there is a big exit down some steps and escalators and near McDonald’s that gets you to Waterloo Road. There are bus stops all along both sides here. To go towards central London, stay on the railway station side.
If you are struggling to find the bus you need, be warned that there are more bus stops to the left, under the bridge and by the IMAX cinema. More stop on York Way (further left).
In theory, bus stops should have maps showing where different buses can be found. Each bus stop has a different letter.
Perhaps the best choice might be the 139 which takes you through Piccadilly Circus, Oxford Street and right through the centre to Golders Green. Stop H is the best for this, by the IMAX.
You can also get a bus (eg 68) to Russell Square, another popular place to stay.