The book "The Ukulele as a Solo Instrument - C Notation: A Collection of Ukulele Solos" was published in 1916. You can now own a copy of this book where the yellow pages have been turned white and clean through the wonders of technology. By N.B. Bailey and Keoki E. Awai.
If you are a beginner, this book is too difficult. If you like fingerpicking and and are interested in very good practice exercises, you will like this book. You can read more about it on my website at http://judyrobinsondesigns.com/2015/01/18/ukulele-solo-book/
This ebook (pdf) will download with 3 parts. The quality works to print or to view on a digital device. Enjoy!