Eliot Coleman's book Four-Season Harvest is a good read to get into the winter garden game. Coleman presents imaginative ways to overcome many seasonal limitations, which can help even the most seasonal gardener comprehend ways to extend crops. Simple graphics are detail rich enough to make Edward Tufte proud of Coleman's 30'x65' garden. As an added bonus this book clearly guides the reader through various structural designs and implementations of cold frames, tunnels and root cellars . Plus there is a good section on composting -- a must for a real gardener :-)
Coleman, Eliot. (1999). Four-Season Harvest.