Using Google Maps with the hotels from Booking.com
Step 1. set a maximum amount of money that you are willing to pay per night.
I don't know which are your preferences, but let's set a price per night of 50-100 EUR in a double room at a hotel located as much as central as it can be :)
If you travel in a group, with family or in a group a 3 friends, the hotel room will be cheaper.
Step 2. Choose a popular area from the city
After I've set a maximum price per night, I'm thinking about the location of the hotel. I would like to be at a walking distance of 10-15 minutes of King's Cross for example.
Don't consider areas such as Westminster, Piccadilly, Hyde Park or anything in Central London. We don't have large budget for now, maybe next time :D
After I've apply the search filters, choose a hotel and click on "Show map" link.
The website will redirect you to the map of King's Cross were you can see other hotels from the area, how close is a tube station and what parks and places to visit are near.
Let's take a look at King's Cross map from below.
Usually, the hotels from the "border" are cheaper; you can click on them to see a room price without leaving the map.
After you've seen them, choose the hotel that's ok for you and book a room.
Where to look for an hotel.
Because the website uses a Google Map, you can see what tube station/restaurants/places to visit are close to your hotel.
I don't know the city very well, but I would search hotels in the following areas:
Before we go on, I need to exclude an hypothesis:
We all know that it's impossible to find a 5* comfort and location by paying only 100 EUR per night...let's stay reasonable and search a medium hotel, with a medium comfort and location.