Here is a simple list of articles I have made in the past.

What is PicoGym

PicoGym is a noncompetitive practice space where you can explore and solve challenges from previously released picoCTF competitions, find fresh never before revealed challenges, and build a knowledge base of cybersecurity skills in a safe environment. Whether you are a cybersecurity professional, competitive hacker or new to CTFs you will find interesting challenges in the picoGym that you can solve at your own pace. Team picoCTF will regularly update this challenge repository so visit the picoGym often. -