There are several things to keep in mind when looking for a beginner guitar. For acoustic guitars, there are three categories: laminate, solid top and fully solid guitars. The laminate is where a the wood has several layers that have been glued together. The solid top guitar, is fully solid piece of wood for the top part of the guitar, with the back and sides being laminate. The fully solid wood guitar, is fully solid wood for both the top and the back and sides.
In my experience, a solid top guitar is way to get good value for less money. One guitar I really like in this category is the Yamaha FG820.
For younger kids, a 3/4 size guitar will be easier for their hands like the Yamaha JR-1 or the Luna Aurora Borealis.
Lastly, one of the best ways to buy a guitar is to go to a guitar store and play several guitars. The one that sounds best, fits your hands and looks great might be the best guitar to buy.