Okay, I'll rephrase that into not knowing how you're organised enough to remember the locations of various handy guides.
It's been a few years now but I think the All-Purpose Guide is most likely to be the one that saved me from seemingly endless frustration. I think exploding arrows seem to come particularly to mind.
I'm often a great hoarder of random things, especially if they're shiny (my character had a great voice for the "ooh, shiny!" phrase: I chose the country girl one because she sounded so un-warrior-like). I wasn't excessively frugal with the malachite gems but still ended up with an enormous pile of the stuff by the end. I was glad I hadn't been so mean as to not help out that blind chap while I was bumbling about.