online courses, tutorials, etc.

DIY/Maker

Disclaimer: most of these sites offer step-by-step instructions -- hardly the maker way, I know. But not only are many of their makes pretty darn inspirational, of the kind that make you say "Well I could do something like that." but they are a great starting point for hacking your own idea.

Coding

MOOCs, etc.

You can take classes on just about any topic in your own time, at your own pace, nearly all for free, and even earn university credit and/or credentials (though those may cost you). Who needs night school any more??