The Treaty of Versailles was signed in June 1919. It was a dictated peace, meaning that Germany didn't have any say in it.

The main terms were:

Blame: Germany was blamed for starting the war (War Guilt Clause - Article 231).
Reparations: Germany had to pay £6.6 billion in compensation (reparations) for the war damage.
Armed Forces: Germany's armed forces were drastically reduced to only 100 000 soldiers, 6 battleships and no air force. The Rhineland was demilitarised.
Territory: Germany lost about 13% of her land including Alsace-Lorraine and parts of West Prussia. She also lost all her overseas colonies. She lost about 10% of her population - approximately 7 million people.

Also, Germany was not allowed to unite with Austria.
The League of Nations was established but Germany was not allowed to join.

Most Germans hated the treaty because:

they expected a fair treaty. The Kaiser had gone and Germany was a democracy. President Woodrow Wilson of the USA had appeared to promise a fair treaty in his Fourteen Points.
it left Germany defenceless and humiliated Germany.
their economy was already ruined from WWI so they couldn't afford the reparations.
the Stab in the Back Myth - many believed that Germany was winning the war so this made it even harder to accept the treaty.

The Treaty of Versailles made the Weimar Government unpopular even though there was nothing they could do about it and it especially angered right wing nationalists. The Treaty directly led to many problems over the next few years including the Kapp Putsch, the invasion of the Ruhr and hyperinflation crisis and the Munich Putsch.

GCSE Germany 1890 - 1945 AQA

The Treaty of Versailles