Well Germany was in a lot of shit after WW1. Basically they were in a ton of chaos and multiple revolts occurred after the treaty of Versailles was signed (including Hitler's Munich putch(I think that's how you spell it)). Germany also had set up a government where parties held seats based on the percentage of votes they got. To get a majority, many parties would form with eachother, and when these parties stopped working together for whatever reason, there was no longer a party with over 50% of the votes, so a new election had to be held (This is all important). Also Germany to try and build up it's economy again took out a lot of loans from America, which worked until 1929 when the depression occurred. Germany was again in deep shit, which lead to Hitler running for office.

Now Hitler promised a lot of things. He promised something to everybody so people supported him. He attacked politicians who supported other parties, making politicians fear him. The major thing he promised was to remove the treaty of Versailles (which every German hated, it would also relieve the German economy). On top of this, he created a scapegoat (the Jews) who he said was the reason Germany lost the war (I'm not sure if hitler stopped paying America it's debts, but I don't think he did). Also you have to remember, Germany was going through a difficult time, and anybody who promised them what he did they woukd've voted for. Hitler then in 1933 gained the position of chancellor in Germany by the current chancellor at the time, believing he could control Hitler. Hitler then called for an election, which his party got a 52% majority.

Hitler then gained total control of Germany. He removed the threat of communism when the Reichstag burned down. He killed his major threat to his power in 1934 at the night of long knives. He i traduced a law which allowed him to create laws without the approval of the German government. This allowed him to remain in power and remove proportional voting.

This is how Hitler came to power. Hitler before WW2 created jobs for the German people, built new roads, reclaimed lost land and took new territory for Germany. He also created Hitler youth, which appealed to the younger generation. Also people followed him in fear of him.