There's plenty of information...get yourself a copy of Republic to Reich I think that book has some good info on Speer. You should also look into Joachim Fest's Book "Speer: A Final Verdict" once you've got the background info on Speer.
You would have to look into many factors, such as his visit to concentration camps (Mauthousen and the DORA facility), and the way he blindly followed Nazi policies. He once said "I had closed my eyes", his many contradictions especially his testimony at Nuremberg and the way he prolonged the war by two years simply to please hitler and advance in his career (no moral or conscious regard for the well being of others in doing so). Also Speer once claimed that he joined teh nazis to advance his career and yet later on he is also quoted as saying that the Nazis represented the ideal society in Germany.
Of great significance is the fact that he claimed to know nothing of the holocaust which is truly unbelievable considering he was responsible for all the war production in Nazi Germany and so would have known about the transport (i.e. trains) that were transporting goods across Europe. The fact that trains carrying Jews were given preference over trains carrying military goods shows how important these trains were to the Nazis, so surely Speer must have known this. I cant remember much more from the top of my head but i hope you get started by reading loads of material - its all out there
