Before you begin training for shinobi..

Read The Book of Five Rings by Miyamoto Musashi.

I will not let you borrow my copy. Shinobi must be able to gather intelligence on their own.

Come to me when you have read The Book, then training will begin.

Everyone needs to read it!

Aww, lookit my Retainer gettin' all philosophical and shit.

...

But serious shit, read it.