This Kindle book is a great intro to Forex trading and explains the 'candlestick charts', such as those on Mt.Gox and how to analyse them. At just 136 pages it helped me a lot:

https://www.amazon.co.uk/gp/product/B005505HBW/ref=kinw_myk_ro_title

http://ecx.images-amazon.com/images/I/51iRlvrhOZL._.jpg