1. start a small fire in the smoker (some use a chimney starter with lump charcoal others use butchers paper from the cook before and kindling)
2. slowly build up a bed of coals using gradually larger pieces of wood until you maintain thin blue smoke at your desired temperature.
dont prematurely put your meat on untill you have a well maintained pit as the smoke profile of the food happens early
it is always recommended that you have a small raging fire than a large dull one.
If you find that you are creating a large hot spot next to the firebox then some move the fire to the middle of the grate rather than up against the wall of the firebox.
Some use a water pan up against the right hand-side to dampen the temps
also, run your pit with the dampers wide open and manage temp using the desired amount of fuel
I also sort my splits into size groups (usually 2-3 different sizes) because as beaver said control temp with the size of fire and by having some different size splits you can further meter your fire size. Remember you always want to see a flame, you will not get clean combustion without it.
It also helps to stage your next log in the fire box (i.e. fire in the back of the box and next log staged at the front)
It is a lot more work doing it that way and you'll be adding a log every 30mins to 1 hour but thats the ONLY way to run an offset in my opinion.