This is one of the best guide written by Eric Zhivalyuk, an tech entrepreneur. Its original purpose is for Bitcoin mining. However, as ASIC devices started to be delivered by Avalon and Butterfly labs, many have been switching their GPU mining rigs for litecoin.
66 page pdf file created for your information. The guide is very in details and worth reading if you seriously want to invest into virtual currencies like bitcoin and litecoin. Download link below: