neil, if you want to learn, don't worry about efficiency first. experiment with all sorts of methodologies: bit and byte logical manipulations, note and observe their characteristics and then decide which is best.

cheatsheets don't teach you the material, exhaustive experimentation does. shortcuts sacrifice your later ability to achieve guru status. lots of programmers... few gurus.

playing with leds is a great start. thats how i teach assembly programming to complete novices. my experience is that people with higher level languages lose their tolerance for assembly language and so never stick with it to learn its real power.

given the choice to make an assembly language programmer out of a office clerk or a pc programmer - i'd choose the former. in fact, i've done it.

duh