Take some newspaper (or any paper that retains its form well when confronted with moisture and pressure) and crumble it into a ball.
Dip the newspaper ball into water. (I hear that the effect is better with a little vinegar in the water)
Then dip it in the ash in the stove with the wet side
Wipe the glass with the newspaper. This may need some pressure.
That's it :)
This process works since the ash can easily bind the soot. The ash and the soot are two complementary parts that are 'created' in the process of burning wood
My personal favourite is to start the next fire, and before the fire gets too hot (after 5 mins?), clean the glass with a cheap scourer and water. If the glass is hot enough to turn water to steam, its too hot (and you will get burned). The elbow grease required for cleaning it when it's warm, compared to cold is trivial.
Very fine wire wool (1000 grade) is the best way to do this. Spray the glass with a little water, then rub firmly with the wire wool.
This was suggested to me by a stove dealer, and is the only method I've found that removes the thickest layers of burnt-on deposits.
Soot is carbon particles that weren't burnt up, and will burn under the right circumstances. A good, complete combustion will burn the soot right off. Try making a fire that burns well (i.e. lots of oxygen), then there should be little to no soot left.
You may need to look into whether your stove burns inefficiently if you are getting large soot deposits on the glass. If the stove burns well, it should burn off the soot itself.
Large quantities of soot is an indicator (and a result of) an incomplete combustion.
This may (as is often the case) be caused by too little oxygen in the stove - that is, too low airflow.
I have found that ashes from the wood burning stove on a damp terry cloth or paper towel work wonders. Then take a second dry terry cloth or dry paper towel and wipe again. Another solution to the problem is using 'Nothings Better' which is a hard water stain remover. Just follow the directions on the container. 'Nothings Better' comes in dry and paste. The dry is what works best my wood burning stove.