Sadly, I realized that it was based on MASM not NASM, which are similar, but NASM is proper for BBC. I guess I will end up ordering a book on NASM.
I wouldn't recommend that, because although BBC BASIC's assembler is more similar to NASM, it is not identical and you would still have to learn the differences. If you've got a book that uses MASM for its examples I'd stick with that and just keep in mind that there will be a few changes necessary.
The only major difference between MASM's instruction syntax and BBC BASIC's is that in MASM memory references are usually implied by the declared variable type, whereas in BBC BASIC (and NASM) you must explicitly enclose the operand in square brackets  to indicate a memory access: