Hacking:
www.vulnhub.com# It contains virtual machines with vulnerabillities to have practice.
https://www.corelan.be# This damn team has reached another level in buffer overflow exploitations, amazing tutorials
http://pentestmonkey.net# This website contains some amazing cheatsheets that can help your life A LOT!
https://blog.g0tmi1k.com/2011/08/basic-linux-privilege-escalation/# This is kind of a tutorial by the amazing g0tm1lk for privilege escalation in linux systems and at the end you can see some automated scripts.
https://github.com/mubix/post-exploitation/wiki/Linux-Post-Exploitation-Command-List#one more linux priv escalation link.
Programming:
www.codeacademy.com# This is a pretty good website for programming like PHP,python,html.
http://learn-c.org# Very good site to learn C and at the top you can find some websites for bash,python and a few others.
Windows Privilege Escalation:
http://www.fuzzysecurity.com/tutorials/16.html
http://www.toshellandback.com/2015/11/24/ms-priv-esc/
http://it-ovid.blogspot.gr/2012/02/windows-privilege-escalation.html
https://www.youtube.com/watch?v=0SjMgnGwpq8
https://github.com/foxglovesec/Potato
https://github.com/shjalayeri/sysret
https://www.youtube.com/watch?v=kMG8IsCohHA
#There arent many tutorials about windows exploitation so i put all the links i have gathered and hopefully will help someone!