When I use a plotter to identify a direction from a VOR, what heading or course is it exactly?
If you are using a sectional chart and a plotter only, with no other information, remember the following:

If you are using the plotter relative to the sectional grid lines, you are measuring True Course.
If you are using the plotter relative to the compass rose around the VOR, you are measuring Magnetic Course.
True and Magnetic Heading can not be measured directly using the sectional and plotter. It must be calculated. You need to have the wind speed and direction to calculate any heading direction. You can calculate True Heading from Magnetic Heading. You can calculate Magnetic Heading from True Heading.
If you are in the aircraft, you can measure your Magnetic Heading by looking at your Magnetic Compass. You can calculate your True Heading from the Magnetic Heading, using the Magnetic Deviation, and the Magnetic Variation. Conversely, you can calculate your Magnetic Heading from your True Heading using the Magnetic Deviation, and the Magnetic Variation.