From the secondary, several thousand volts but low amps (probably a few hundred mA, if that). The primary will likely be low voltage, with slightly higher amperage.
Both will be outputting pulsed DC, and you won't be able to measure the output easily with a multimeter (whatever you measure will likely be a "ballpark average"). What you really want to use is an oscilloscope (at least to know the voltage; regardless of the primary or secondary, the output current is likely small - call it an amp or two). If you are intending on measuring the secondary, you will need a high-voltage probe for the scope (most scopes only go up to a few hundred volts or so of range). The purpose of using a scope to measure the voltage is so you can see the series of voltage pulses over the time-period you have the scope set for; in other words you can see the tops of the peaks, and know the actual "peak voltage" vs the average you would get on a multi-meter between the peaks and the valleys.