Learn these chords and explore these websites as a group. Look at the songs you would like to learn.
www.scorpexuke.com has a library of over 1100 songs, all clearly and accurately presented in a printable format, with chord diagrams. It is easy to search, and shows the number of chords in each song, to make choosing for beginner and developing players easy. Highly recommended, although there are not too many really up-to-date songs.
www.ukutabs.com as mentioned above, has really accurate chord charts, which are clearly presented if you are reading off the computer screen: less good for putting into a printable format. The ever-growing range of songs includes up-to-date pop songs that your students will love playing. There is even a really handy transposing facility.
www.ukulelehunt.com is a comprehensive ukulele website that features chord charts and tabs for song arranged by genre and by difficulty.
Explore playing with the rhythm of your playing. One common way is
Revise the chord diagrams - https://quizlet.com/_gzl5u