Don't feel too stupid - it took me about four years to figure this out, and this was after taking an out of hours course on essay writing (which proved to be more confusing than writing an essay) and it wasn't until my biology lecturer spent an entire double lecture talking about "the basics" like how to do a proper biological drawing, how to write a practical report, the conventions for naming oders, generas and species, and referencing. We had refresher referencing lectures later in the semester.

LKH really hasn't got any excuse for not using a proper referencing system - biology hammers it in that you're only as good as your references and you have to be specific enough that any Plebe as well as your lecturer can pick out the book you used and find your reference. English you can get away with fudging things a bit more (I know I once got marked down for putting too much detail into my bibliography) but having a clear reference list helps so, so much.

Just as a tip, you can't really go wrong with the Harvard system. It's like the standard referencing system that everyone EVAR uses.