Where can I found a book or an online tutorial of how to get a signed card into an orange.

In the Thread "Secret Sessions" but you need 50 posts to access.

Yeah I'm working on that but since I'm not on it I'm trying to learn as much as I can.

Javi, this question usually gets the Café buzzing : "Hey guys, what's the best card to orange?"... you should end up with a lot of answers...

Many Versions of "card in fruit" have been included in books and video for generations either using a selected playing card or a borrow dollar. You may want to pick up a book like Mark Wilson's Complete Course in Magic. This book is great for beginners to long term students.

Larry Jennings' Neoclassics by Stephen Minch.

Magicfish says the Jennings' routine.
The card is not signed.
However - the torn corner is a fine substitute, and the routine is beautiful. Highly recommended.

First 'Card to Orange' has always been the staple of my act. It has been my closer for 20 years.
Second please please please use the search function. There is a wealth of information hidden in the Café. Just go to the top right and click on search. "Open Sesame", as we say in France.

Tarbell 1 has this

I remember doing this effect many years ago in a parlour show. I did it with the “torn corner” that matches. After the show a friend of mine commented that the corners don’t “really” match. I said that they do match. However since then I was left wondering: how many spectators are left with the feeling that the card is not actually the same card?

Never ever did anyone comment on that. The funny bit is that most people wonder how in the world a playing card ends up in an orange. When at the end of the trick you show the card and add the missing piece it's an additional kicker. But in their minds they get stuck thinking about the puzzle of on object in an impossible location, the rest just flies.

Magicfish is right. The Jenning's routine is great. The deck is tossed into the air and it turns into an orange--it is caught on point of a butterfly knife that is drawn and opened in a fancy way. It is the most logical of these effects. The deck "turns" into an orange and the chosen card is inside. I really highly recommend it.