Not a huge amount to add but I'd recommend using the app City Mapper to help you with getting around. Google Maps works well too but City Mapper can be smarter about timings, alternative routes and helpfully tells you which end of the tube / lizzy line train to be at for your exit. For the latter, the platforms are so long that it really pays to be at the right end.

If just walking around, then Google Maps is better as you can put the phone in your pocket and set it to vibrate when you need to turn.