1. Try and think as abstractly as possible about what you are trying to do, and don't immediately jump to the technical solution you think you know. For example, routing - I've often seen people mapping custom MVC routes (because mapping routes is what you do in MVC) in order to get "content X to show up at URL Y" but Umbraco gives you many options, that are often easier/better etc.
2. This right here - the community. While the docs are great, and will tell you how to do pretty much anything you want, what they're usually missing is the why and sometimes that's important - especially in cases where Umbraco deviates from what's "normal". Between GitHub, Our, here, Twitter etc. it's really easy to reach out and get that info.