Making good use of the MIT Hobby Shop, I learned the basics of boxmaking. If you're interested in learning the details of small woodwork, joining, planing, and general box making, I recommend a book by Doug Stowe called Basic Box Making. I'm sure you can find tons of information for free online, but that book is the one I used, and it was very helpful.
Here is the first type of box I made. It's a cute little one for holding trinkets and small things. I learned how to book-match wood, join corners with keys, and generally learned my way around the shop. I actually made two, with slightly differing lids. The box is mostly made of cherry, and the corner keys are walnut. The whole thing was finished off with Danish oil.
This box is a multipurpose one that I made for my girlfriend. She uses it to store all sorts of things, though it was designed to be large enough to hold letters. The box is mostly walnut, but the corner keys are made of maple. The top surface shown is a birch plywood that is cherry veneered on the inside, but I made a nice top panel (not pictured) out of a beautiful birdseye maple. The box was finished with some Danish oil to bring out the color and grain patterns.