Which AWS manual? There are about a billion of them. A2.4 covers welding symbols, but a lot of it is superfluous (if you can memorize how a welding symbol is constructed, you can often tell what process/size/pitch/finish/contour/etc is being asked for). Most code books don't offer any practical knowledge that can be applied towards anything, and most of the calculations in any of them whether it be ASME, AWS, etc are very application specific, and I'd find it hard to believe that an exam question would reference any of that.
One of the cheapest, best books on welding you could ever purchase is The Procedure Handbook of Arc Welding, sold by the Lincoln Foundation. It's a hefty book, touches virtually every welding-related topic from symbols to electrical characteristics to estimating production, is DIRT CHEAP, and is often referred to as the "Welding Bible" by most.
