National Geographic Visual History of the World, or NGH for short, is an extensive, well-illustrated, up-to-date book covering the history of humankind from the appearance of the first hominids to about 2005. It's concise, accessible to non-scholarly readers and can be a great fun just to browse through the illustrations, but it doesn't contain any meaningful maps!
With illustrations being its main selling point NGH presents us mostly with a treasure trove of images of historic figures and buildings, and of other artefacts like art, tools and weapons. They are numbered and linked to the corresponding text, even if they relate to it only vaguely. On the other hand, with often a dozen pictures per spread it's easy to forget they should be useful as well as numerous.
Surprisingly there are hardly any maps and this is NGH's biggest minus. A historical atlas is a required companion, or in case of Philip's Atlas of World History(Hardcover) a worthy substitute with plenty of text and abundance of maps, charts and an occasional picture.
NGH has an easy to follow format. The world history is divided into eight periods, from pre-history to the modern times, each color-coded for easy search. Each period is divided into much smaller sections. With about 120 sections in total a typical section focuses on one subject like a country or an event, with one page being a section introduction, for example "The Kingdom of Franks" and another one or a few pages more specific - "The Rise of Carolingians", "Charlemagne's Wars", and "The Empire of Charlemagne" for example.
At the bottom of each age there is a timeline of the period concerned, but naturally they often overlap. This is a clear layout of data that is both easy to follow and easy to search - the NGH's biggest plus.
National Geographic is a very trustworthy publisher, but a book of this scope is bound to contain some errors or bones of contention. For example, on page 20 it states that 'around 40,000 years ago, modern Homo sapiens, in the form of the Cro-Magnon man, finally migrated out of Africa to Europe.' This is an over-simplification at best. Homo sapiens had made a long detour in Middle Asia before populating Europe.
Also, for the earliest history it follows the middle chronology (reign of Hammurabi 1792 ' 1750 BCE), instead of recently more supported short chronology (1728 ' 1686 BCE). By the way, Hammurabi is spelt Hammurapi in NGH. While it's not a mistake, NGH doesn't specify which chronology it chose to follow, which makes it more confusing if you want to consult other sources.
For a world history book it's slightly too concerned with the Western hemisphere, but other regions are fairly and consistently covered as well.
NGH's main competitor in books is DK History: The Definitive Visual Guide : From the Dawn of Civilization to the Present Day (Hardcover) or DKH for short.
They are quite similar, both are about the same size, are fairly recent and up to date and of course come with a wealth of illustrations. The main difference is the price - NGH is much cheaper, which is also the reason why I chose it. However, DKH contains maps, graphs, etc, making it worth paying a few bucks extra. But on the whole they present history in different ways and focus on other details, but it's a matter of personal preference which book does it better.
I also believe it still competes well against online sources like Wikipedia, especially thanks to the illustrations and conciseness, but if you want to read about anything in more detail, Wikipedia wins hands down.
To sum up, NGH is well worth the price, but it would be more informative with maps.