OTC products reference...please help

Hi ya'll,
Is there any good books/references on OTC drugs in precise, easy-to-use category? I've heard of the mosby ( http://www.amazon.com/Mosbys-Drugs-Over-counter-Professionals/dp/081518395X/ref=sr_1_2?ie=UTF8&s=books&qid=1214099647&sr=1-2 ) but am not sure if it's worth the money to buy. To me, this OTC recommendation is the only "clinical" aspect of retail...sorry to vent but I've just had a bad day at retail where people yelled at me for "why do you increase my copay to 50$, I normally pay only 25$ for all those brand names drugs" (this is for Augmentin). And thus need some things brainy to pursue now.
Anyhow, any recommendations on OTC references is truly appreciated guys

 

Thanks guys. I'm looking into this book, it seems to be really comprehensive, which is good. But it's quite pricey and there are no used ones on amazon. Man, I'm having pocket-itis already these days