Judo
Juudou
noun
The gentle path is, surprisingly, judo. Yep, the sport / art based on throwing people around.
じゅうどう
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
もし柔道が何かを知らないって言うなら、ここに超簡単な入門書があるよ。
If you don’t know what Judo is, here is a book with a very brief introduction of it.