Here's what you should know (I hope I didn't leave anything out) before WWII
Churchill early years;
Left school to go to the Queen's Royal Hussars. Travelled around the British empire, including India. Boer war.
Escaped from South Africa imprisonment. Became quite popular as a journalist (mother was American whom had links with American journalist and newspapers > NY times)
Became an MP, standing for the Conservatives. Left Conservatives due to free trade disagreement. Joined Liberals. Held positions such as Lord of the Admiralty, Home Secretary, Minister of Munitions.
Siege of Sidney Street
Issues with Irish rebels and nationalists.
Dardanelles/Gallipoli campaign.
1920's;
After standing as an independant MP, he joined Conservatives again.
Return to Gold standard (Chancellor of the Exchequer)
General strike
His trips to America before, during, and after the Wall Street crash.
Losing his government position in 1929.
1930's;
Indian dominion status
Abdication/constitution crisis of King Edward VIII
Opposing the policy of appeasement
Named Lord of the Admiralty, 1939.