Lonely Planet is in my opinion the best general guidebook to the world. There may some local books that are better for specific cities but few that can match it across the board for detail and insight into countries and regions.
http://www.lonelyplanet.com/worldguide/

In any case, the Lonely Planet web site is superb. it starts with a map. Click the continent and then the country. I went to the country that I wanted to get more information on: China. Here is what it said:

http://www.lonelyplanet.com/worldgui...ons/asia/china
China isn't a country - it's a different world. Unless you have a couple of years and unlimited patience, it's best to follow a loose itinerary here, such as following the Silk Road, sailing down the Yangzi River, or exploring the Dr Seuss landscape of Guangxi Province.

From shop-till-you-drop metropolises to the desert landscapes of Xinjiang, China is a land of cultural and geographic schisms. It's not that it has completely done away with its Maoist past - it's more that the yin of revolutionary zeal is being balanced by the yang of economic pragmatism.


When To Go

Spring (March-April) and autumn (September-October) are the best times to visit China, though the higher altitude areas of Tibet, Qinghai and Western Sichuan are best visited in high summer (June-September). Daytime temperatures range from 20°C to 30°C (68°F-86°F) in these seasons - but bear in mind that nights can still be bitterly cold and it can sometimes be wet and miserable. Major public holidays, in particular Chinese New Year, are best avoided as it's difficult to get around and/or find accommodation.

Guidebooks Confiscated

Travellers entering China by road or rail across the southeastern border, particularly the Vietnamese frontier, report that Lonely Planet China guidebooks have been confiscated by border officials. This is due to sensitivity regarding maps of China that do not include Taiwan. Travellers should consider putting a cover on the book to make it less recognisable and just to be safe, copy down any crucial details you might need while in the country.

For good advice from other travellers check out the Thorn Tree travel forum.
Wise.