Gregory's ServerWhat's always been the most help for me is good built-in documentation. PowerShell is amazing for this, every command has huge info pages with many examples, all just a `help $command` away!
In unix shells, man pages are alright and it helps to get comfy with how to use and search them. A third-party helper like tldr or woman-pages (in emacs, also a great app for built-in help) can make that a little nicer.