Happy/Worship Hebrew or Yiddish songs?

"some more very happy, beautiful, worship, etc. songs"

There are many thousands of "happy and beautiful" songs.

(EDIT: I now see that you want "very happy", not just "happy". Well, for me almost everything is "very happy".)

-

"I would like to use them in a book I'm writing"

Well, if you want easy work, pick a traditional Hassidic song because they have only one or two sentences/verses (repeating like a mantra). E.g.:

- "amar rabbi akiva" (http://www.youtube.com/watch?v=IZ-hpgUxAJ4 ) (Words: "Rabbi Akiva said: You are fortunate, Israel; Before whom you purify yourselves, and who purifies you? Your Father in Heaven.")

- "rahamana" (http://www.youtube.com/watch?v=Urqz7920g60 http://www.youtube.com/watch?v=RcmlnIiVByc ) (Words: "The Gd who answers the poor: answer us! The Gd who answers the heartbroken: answer us!") Technically, it's perhaps not "very happy", but the music is upbeat.

There are hundreds like this.

Or you can pick a different direction. A longer song from a different diaspora. A very quick selection:

- "Ehye asher Ehye" (http://www.youtube.com/watch?v=Kpx618dfyxQ http://www.youtube.com/watch?v=6o7dWC9AawY )

- "Lover from the Mor mountain" ((Lover = Gd, Mor (myrtle) = Moria) http://www.youtube.com/watch?v=68M79Ml3mOs Different words, similar melody: http://www.youtube.com/watch?v=BP400Rvib6Y http://www.youtube.com/watch?v=rSyQNaEU_cQ )

- "Im Tehfeza" ( http://www.youtube.com/watch?v=mRlpiFza7bI )

The words and melodies of all the above are public domain (well, the last vid is a modernized arrangement of a traditional melody).

Again: there are thousands (tens of thousands, actually) of songs so it's hard for me to pick.