normally burning oil is either rings or intake valve seals. exhaust valve seals let oil out of the exhaust unburnt. you can normally narrow it down by running the engine and see if the oil cap is under pressure, that will normally mean rings.
start the engine and open the oil cap to see if it has a lot of pressure or flow of "air" out. if it does not i would lean towards valve seals, or head gasket. both of which can be done with some simple tools if you know what your doing.