The software
nomike's Ukulele Songbook is also an open source software which you can use to create your own songbook with your own selection of songs.
More documentation on this is available on its github page.
The songs
If you want to have a song added to the songbook or if you found an error, please contact me.
Variants
Besides coming in a guitar and an ukulele flavor, the songbooks are released as regular and printshop variant. If you're printing this yourself, you almost certainly want to print the regular version.
Regular
This is the standard version of the songbook. Songs are always in alphabetical order. If a song has an odd number of pages, empty pages are inserted to ensure the next song starts on the left page. This prevents unnecessary page flipping while playing. If songs are corrected or new songs are added, you can simply print the changes/additions and update your local copy without having to reprint everything. See the update instructions for keeping your copy up to date.
Printshop
A nicer version of the songbook, featuring page numbers and clickable links in the table of contents. However this comes at the cost of printed copies not being updateable like the regular songbooks.
Additionally the songs are not in perfect alphabetical order to avoid blank pages while still trying to have songs start on the left page to avoid unnecessary page flipping whil you are playing. If you want to have this professionally printed and caseworked, this is the version you might want to use but if not you should stick to the regular version.