Although I do not train in Yoshinkan Aikido, I do feel very strongly that Shioda Gozo's Aikido Shugyo. The anecdotes Shioda-sensei uses to communicate his insight and understanding of the technique/application of aikido will assist beginners, more advanced students and teachers. What I found to be most beneficial was how it helped stimulate my transition in various levels of aikido as I read and reread the book. I highly recommend it all serious aikidoka.
Just in case you would like to order the book, here is the webiste: http://www.shindokanbooks.com/shugyo.shtml
Happy reading...and happier practicing!