Generic software & improvement
Methods & Tools is a free software development magazine. It has 4 publications per year.
Kanban / Flux
Une très bonne compilation des différentes interprétations d’un CFD: http://brodzinski.com/2013/07/cumulative-flow-diagram.html
Personal Improvement
the famous personal kanban: http://www.personalkanban.com
Free programming books
Many links with free books in many languages: https://github.com/vhf/free-programming-books
And another list: https://github.com/sindresorhus/awesome