Reading stories together has so many benefits. As well as just being a nice thing to do together, it really does underpin literacy development.
Young children often choose to re-read the same story many, many times. Through this repetition they are doing some really important learning and it will give you lots of chances to practise your use of AAC alongside the book!
If you have the correct software (Boardmaker, Communicate in Print or Symbolmate) you can download editable versions of these here.