Whilst the in-game Tutorials are okayish (but somewhat scarce), I discovered that the video tutorials by this dude are simply awesome. He gives you the insights fast and saves a lot of frustration playing this awesome game.

Its by far better than manual, ingame help, kerbal wiki - combined.

Enjoy and add your help resources too!

Link

Dunno. For me, trying to find my own way, failing explosively, and checking online (wiki, mostly) only if I'm stuck is a big part of the fun of the game. Video tutorials tend to give you too much of the solution right at the beginning, there's not much left to figure out for yourself.

But I'll look at these ones for the things I think I mastered. Always cool to see how others are doing stuff :)

Try some of Scott Manley's tutorials, they gave me some of the basics without giving the whole game away:

www.youtube.com/playlist?list=PLYu7z3I8tdEm5nyZU3a-O2ak6mBYXWPAL