you mentioned you couldn't afford to buy them, which i can understand. barring the suggestions given to you on this thread, you actually could buy a set fairly cheap from jepp. i used to get texas only every few months for only around $25. can you afford that? you get everything you need in the package, including the legend, which makes it helpful to study the charts if that is what you are going to do (for an interview, for example).
FYI it's called Airway Manual Express according to their website...i couldn't find the price