If you plan to learn Russian in London and have decided to try learning Russian with a private tutor you should probably check the Russian alphabet before your first lesson. Getting familiar with the Russian script, even if you cant really read it yet, will help you to focus on the actual language in your first lessons and allow you to take full advantage of your private classes. The Russian grammar and vocabulary, like in other East European languages is somehow different and rather more complicated then what English speakers are used to.  If you are already familiar with the language and want to reinforce your understanding and build your confidence, have a look at Practice Russian. They have a great variety of activities and the language is explained in a very clear manner.