For Guitar:

Hal Leonard Guitar Method Book 1 - Great for learning the foundations of reading music for guitar. 

Guitar for Kids Method & Songbook - For kids 10 and younger. Starts with easy one finger chords, notes on the first three strings, and includes a fun songbook with easy chords. 

Theory for the Contemporary Guitarist - Great for older teens and adults that seek to understand the guitar and music theory on a deeper level instead of "just memorizing songs." Includes short quizzes (with answers) to assess your knowledge on each topic.

For Uke:

Ukulele Method Book 1 - Great for learning the foundations of reading music and learning easy chords for the uke. 

For Bass:

Bass Method Book 1 - Great for learning the foundations of reading music for bass.