The Bill Bulfer 737NG specific to Ryanair is a good purchase. It's not the SOP's but covers the aircraft very well and you'll probably find it useful for the tech side of things. The SOP's will be hammered in with a large mallet during your practice on the "cardboard bomber", the IPT training and of course the SIM. Once you know who your sim buddy is, ensure you work together at every opportunity on the SOP's because the SIM is only to practice what you already learned.
Work hard and enjoy yourself. Good luck.