The theory test book is a great bit of advice, the book I got actually combined the bus and lorry theory questions so I actually ended learning a lot of irrelevant details.... Only to then learn there was a key code at the back of the book to show me which were relevant for bus or lorry or both!, so just make sure u look at that!
Best advice I was given is always check the height of your vehicle, the amount of times I was given a double decker for private school hires when I had a low bridge on route was crazy, but knowing exactly what height I had meant that thankfully I never created an open top bus!