Roger Jegerlehner's Intel code table provides a useful summary of opcodes. We used the succinct summary of AT&T syntax by Vivek and a few of the easier sections of IA-32Intel® Architecture, Software Developer’s Manual Volume 2: Instruction Set Reference and of Agner's Software Optimization Resources. The last two are certainly not written for school students, but they do give you an idea of the complexity of some of the resources available to programmers.

Programming - a skill for life!

In-line assembler with Intel and AT&T syntax, addressing methods and encryption