Well, the one I had from the age of 5 was the time-life book "Universe". It was my prized possession - didn't understand any of it till much later.
The one I would suggest is Norton's star atlas. Out of print at the moment but you can find good copies secondhand. Has lots of simple how-to's on setting up the telescope and using it, handy facts and figures on the solar system, some nice pics and the maps are perfect for a beginner.
Some of it will be beyond him now but he should pick it up as his understanding grows.
Another great gift is a planisphere - usually the Phillips ones which are in 2 sizes; give home the large one as the small one is too small for anything much. One of these
http://shop.australiangeographic.com...anisphere.html
Note - you must find one for his southern latitude - don't just buy one off eBay because it's cheap - chances are it will be for the wrong hemisphere and wrong latitude.