As a London travel guide, I almost always encourage my clients to take a London walking tour, either on their own, or with the help of a qualified London walking guide. London is actually a great city for walking. Exploring this great city by walking is also a great way to get to know London. It also affords you the opportunity to get some great pictures of extraordinary places in London that you otherwise might not see.
I have 2 walks of my own that I've taken on almost every one of my return visits to London. My Westminster Walk and my Thames Walk. Feel free to contact me about them. I'll be happy to provide you with the details.
Alternatively, there are 2 London walking tour guides I highly recommend. Matt Gedge, an accredited tour guide for both City of London & City of Westminster, while Joanna Moncrieff is accredited with the City of Westminster.
Fun London Tours Matt Gedge provides truly wonderful walking tours, including a unique walking tour that includes The Changing Of The Guard Ceremony from a unique perspective that makes viewing this ceremony far more interesting than the point of view from which it is commonly viewed. Matt has also earned a 'Recommended on Trip Adviser' badge. Matt's website can be viewed here.
Joanna Moncrieff has lived in London her entire life, and has been a qualified City of Westminster Walking Tour Guide since 2009. Her walks include food and drink themed walks, many of which include historic pubs, and she even offers an afternoon tea themed walk! Joanna's website can be viewed here.