Getting started

Stumbled across the GAAA book while on vacation last month. Couldn't wait to start on it! I'm a (self-taught, mainly cold-season!) knitter of about 15 years, but I've never used charts before and my most complicated projects to this point are socks with easy cable designs. Just started a little practice square (Belanger) last night to get my courage up before I invest in $100+ dollars in yarn. :-) I'm up for the challenge though--I hope! Any advice?