For most (almost all) woodstoves, you should burn nothing but seasoned cord wood. Any wood species can be burned (some are considered less desirable only because they are difficult to split or have sticky sap in their bark).
Never burn anything that is excessively dry, such as lumber, certain kiln dried products, or "gray" wood (dead trees or firewood that has been sitting out to dry for too long, usually several years - feels bone dry, is lighter than typical wood, and has a gray color). Excessively dry wood can cause an over-firing condition for your stove, resulting in permanent damage or in the worst case, a house fire. For a description of the damage that can be caused from burning overly dry wood see this discussion thread.
painted or treated wood, or wood products containing glue. Never burn magazines, cereal boxes, gift wrap, or colored paper of any kind (including the comics section of a newspaper). They all produce particles that can clog a wood stove's air passages and can also produce noxious, corrosive or even carcinogenic gases.
See: The Center for Disease Control's Wood Stove/Respiratory Hazards Page
for more information.
And from the EPA:
burn household garbage
or cardboard. Plastics and the colored ink on magazines, boxes, and wrappers produce harmful chemicals when burned.
burn coated, painted, or pressure-treated wood because it releases toxic chemicals when burned.
pressure treated wood may contain arsenic, poisons or insecticides that make insects not eat the wood. any finished wood,paint,stain,varmish or clear coat all release corrosive & toxic gases when burned. They will rust your stove & harm your lungs.
burn ocean driftwood, plywood, particle board, or any wood with glue on or in it. They all release toxic chemicals when burned. ocean driftwood contains sea salt & other minerals that release corrosive,toxic gases when burned. woods with glue in them,plywood,particle board & such, release toxic gasses & nitrious oxide , which will overfire your stove, just like nitrous does to a race engine.
burn wet, rotted, diseased, or moldy wood. Wet wood smokes , rotted wood sometimes stinks horribably when burned & deseased & moldy wood will make you sick from bacteria,mold,mildew,fungus & virus infections when handeling the wood.
Only bring into your home the amount of wood needed for a day to reduce the chance of allergy-causing mold spores circulating indoors.;Things_you_should_not_burn