Below are the books that I recommend you buy in order to prepare for the new Design and Technology GCSE (9-1):

AQA GCSE (9-1) Design & Technology 8552

AQA GCSE (9-1) Design and Technology: Textile-Based Materials

AQA GCSE (9-1) Design and Technology: Paper and Boards

New Grade 9-1 GCSE Design & Technology AQA Revision Guide

AQA GCSE Design & Technology All-in-One Revision and Practice (Collins GCSE 9-1 Revision)