The trove of documents published yesterday by more than 100 news outlets around the world yesterday has been dubbed the "Panama Papers," since the 11.5 million internal documents come from a law firm Mossack Fonseca in that country. In short, the papers reveal how some of the world's wealthiest and most powerful, including Russia's Vladimir Putin, Syrian president Bashar al-Assad, the Japanese and Sicilian mafias, the president of Iceland, and even movie stars like Jackie Chan, all use anonymous shell corporation to hide their millions (and billions.)
It's important to note that offshore structures created to reduce taxes are legal in many cases. Still, the hundreds of journalists poring through the papers have uncovered plenty of apparent illegal activity so far. Here's a list of resources from around the web that provide the most pertinent information about the papers:
The BBC has a great breakdown of what the papers contain.
Reddit has a nice introduction to the Panama Papers.
Fusion has a list of the famous people found in the papers so far.
Here's a cool map that shows where companies and people who are mentioned in the papers are located around the globe.