I am an Eagle Scout, and have worked at a BSA summer camp. For reasons that shall go undisclosed, we often built bonfires which were designed to collapse on purpose (but always without hurting anyone.) Like a logger felling a tree, I learned a lot about the structure of a fire by trying to get it to collapse in a particular way at a particular time. This instructable makes up a good portion of what I learned about getting a fire to burn properly. I may save the other knowledge for another instructable.
Step 1: Basic fire-building
Fire needs fuel, oxygen and heat. If you hold a candle to a log, it will not light, but why? There is certainly enough fuel (see big log), and there is air all around it, and I have heat. Formula no work...Og no cook dinner. There are some people who understand this, yet still pile logs on top of each-other and stuff the whole thing to the gills with newspaper, and wonder why the newspaper just smolders and goes out.
Two keys here: surface area, and airflow. To catch a flame (and especially a spark) you need as much surface area as possible for your flame to catch (which is why newspaper works so well.) But you also need air to be able to circulate and get to where the flame is. If you need a reason, look up oxidation. In a fire, cool air has to come in from the bottom to replace the hot air escaping from the top. Keep that in mind when building any fire.
** The best tip in the whole instructable: Most people will blow on a fire that looks like it needs a little extra kick to get going really well. Do not think that this means that more blowing equals more fire. Almost everyone blows too hard and too quickly which just makes things worse. Blow at the bottom of the flames with a slow steady breath, you will hear a difference when the flames get that "turbo charge" you are looking for. You want to keep that slow stream going as long as possible, so regulate your breath. The sound is really the key here, but you'll get the hang of it. **
The fuel with the most surface area to combustible material ratio is called tinder which ranges from clumps of tiny fibers which catch quickly to sticks no thicker than a blade of grass. Next is kindling which can be about as big as your thumb. When building a bonfire, what you are really interested in is fuel. This is what really burns for a long time, gives off a lot of heat, and provides the structure for the fire. Once you have fuel going, the fire is well established; you don't have to keep feeding it, it's certainly too late to move it, and you don't want to be poking and prodding it too much lest you do more damage than good. It is often a good idea to add pockets of kindling dispersed evenly in the fuel to help ensure that everything catches together. But before we get to the big flames...