Best Practice for Security
You can find all the GlobaLeaks Security Advice for Whistleblowers here. We have copied-pasted the most important parts, but we strongly recommend you to read the whole document.

Social Protection

What follows is a minimum set of actions you should take to protect yourself in social situations.

Technical Protection

Due to the technical complexity of modern computing and network systems, understanding how to protect yourself can be difficult. It is possible to do, but it can be complicated. You should also understand that nobody understands every detail of computer and network systems, including the authors of this document.

However, if you strictly follow the guidelines below, you should be safe enough.