I'm with IR on this one, don't burn wood to sterilize the compost, because that would really only sterilize the outermost area of the heap and you'll risk getting too many ashes mixed in with the soil.
Some people like to bake their soil in an oven at about 180-200 degrees. I tried that once, but that wasn't for me... too smelly. Now, when I have to use soil that's not pre-sterilized, I like to pour all the soil into a large (and thick) clear plastic bag, and leave it on my back porch, where it gets the most amount of sunlight each day. Some people prefer black trash bags, so it's not quite as noticeable that fifty pounds of soil are sitting in a bag on your back porch. But I don't have to worry about nosy neighbors seeing what's on my porch, and clear plastic bags allow more UV light to get inside, which, coupled with the heat from the sun, does a great job at ensuring that no weeds or pests survive.
If you decide to try this, I'd make sure you have at least 3-4 weeks of exposure to the sun before bringing it inside. Every couple of days also make sure to shift the soil around so that all areas are eventually exposed to the light. In the Summer months, you can usually shave a week or so out of the time needed to do this, depending on where you live.
Hope that helps.
