Ultimately our goal is to play over real tunes within our grasp, like some of the tracks from 'Kind of Blue' mentioned above like 'All Blues’ or ‘Freddie Freeloader’. Build a collection of music you can accompany, maybe from YouTube, Spotify, iTunes or your own collection. You’ll find scores in ‘Fake Book’/ ‘Real Book’ compilations which you’ll find online and in larger music book shops like London's Foyles or Chappells. There’s also an ‘iReal Book’ available for iPad and iPhone users which has chord progressions that can be slowed or transposed, but it doesn’t have melody notation so it doesn’t help you learn ‘heads’ visually and may not yet be available for PC/Android. The AB CDs at grades 4 & 5 don’t have an accompanying booklet but use the AB ‘Fake Book’ which comprises their selection of 100 jazz tunes. In my view though, there's no substitute for playing over real jazz recordings so I'd recommend a lifetime habit of putting together playlists of material that invite you to join in.
Playing with recordings also develops rhythmic consistency and accurate intonation by ear more soulfully and meaningfully than working visually with a metronome or tuner.
As jazz teacher Conrad Cork says: ‘Jazz practice is not about the endless rehearsal of scales and arpeggios. Real practice is space to feel a song, think about it, get to know it, play it – maybe fumblingly at first - and progressively master it’.