You have to pick:

I wouldn't kill Hitler. It would be cathartic, sure, but I suspect that it's actually not going to do much good in the long run. I believe Hitler was more a *symptom* of Germany's dysfunctional social and economic state in the 30s than the *cause* of it. If I were to kill him I suspect World War II or something much like it would still happen, and there's a risk that Germany might wind up led by someone competant instead of that raving lunatic.

No, given that World War II is still a decade away, I think a better way of preventing it would be to make the world as a whole a better place, and therefore butterfly the whole problem away. So I'm going to get some clothing that's made entirely out of microfilm containing as much information as I can pack into it about the technological and social advances of the next eighty years, as well as a bunch of secrets that can be easily verified to prove that the rest of the knowledge on the microfilm is legit (eg, the location of treasures, mathematical proofs, that sort of thing). Historical information will include details about how to successfully end the Great Depression (it just started at the end of 1929 so I might be able to nip it right in the bud) and to improve the economic conditions that would otherwise have led to WWII and the Cold War.

Part of my preparation will be researching who the best person to bring this information to will be, but as a first guess Calvin Coolidge seems like a good bet. He's a bit laissaiz-faire for my tastes but was a champion of the middle class and both popular and pragmatic. I'll use the time travel jump to appear right in front of him, hopefully lending further impact to the information I'll convey.

"It's okay, everyone. Calm down. I know this looks bad, but trust me - an internet web page told me that baby was going to grow up to be like Hitler. So this was for the best, no need to get upset."