When your're ready to play more challenging tunes, try this book. It contains 10 original tunes by Andrew G. Gordon, a professional session musician for over 40 years. The tunes are examples of blues, jazz, R & B, boogie woogie, and represent variations on standard forms.
The cd includes examples of all the tunes, with right and left hands recorded on separate channels for study purposes. There are slower versions of the hardest six tunes also.
When you want tunes of an easier level, try Volume I.