If you are new to PowerBI or just looking where you can keep up to date with the technology, the following links are a great place to start.
This is the site for news, tips, ideas, and updates around PowerBI. The site is written by the Microsoft team and is the first place to go to keep up to date.
PowerBI Solutions and Examples
See what PowerBI can do. This site has a great set of example solutions and write ups on not only what is possible, but also real world solutions. You can really get the mind flowing around your own needs and requirements found on this site.
This site is an initial introduction and a great place to start if you are new to the technology. The site changes often and includes video testimonials and demos. Mostly marketing but a great overview of what you can do and a great place to start.
The PowerBI YouTube channel is a great place to discover the technology. Most of the videos are small bit sized chunks, but cover off an introduction to various feature.