The bill Buffer guides are Boeing only. The OP also asks about the MCDU which is Airbus.
I have used four types of FMC in my career, and all are different. The problem with the guides are that they don't make much sense unless you have the box in front of you. Of course, the simulators have the boxes, but sim time is limited and expensive. Some airlines have computer FMC trainers and there's no harm in getting your company to request the use of those. Also, there are some discs around for use on a PC.