There’s a lot of good stuff on DefendTheWeb.net, but what other resources are you using to develop new skills?
I spend some time on https://crackmes.one/ to get more exposure to reverse engineering and keygenning, and have just started using http://www.dvwa.co.uk/ to practice SQL injections and a few other web-app attacks.
I haven’t started yet and haven’t looked, but, in a few weeks/months, I’ll be working on OS, application and user-level attacks in other places.
What other resources are you using?