One of the most important thing for a beginning sailor to develop is a sense of "wind awareness." You need to be able to feel the wind, see the wind and anticipate the wind. Let's worry about see and feel first. Look for things on shore (flags, trees, wind indicators) to help you determine the wind's direction and speed. Also, feel the wind on your arms, neck, face (I use my ears...weird, I know....) Once you can determine where the wind is coming from, you can trim your sails properly.
Okay, back to the business of "terms." If you are just starting out, be aware that there are terms, but don't worry if you can't remember them all. Here is a diagram of the Points of Sail in PDF format. Take a moment and look at it now. What you should be looking at is the relationship of the Wind to the Sail and the Sail to the Boat. When we are sailing close to the eye of the wind, the sail is all the way in. As we move the bow of the boat away from the wind, we let the sail out. We do this to keep the relationship of the sail to the wind roughly the same. Let me say that differently. We move the boat underneath the sail, keeping the angle of the sail to the wind the same, while pointing the boat in a new direction.
Confused? No problem. The point is that the closer your bow is to the eye of the wind, the further in you should pull the sail, and the further away from the eye of the wind the bow is are, the further out your sails should be.
So what about Downwind? Okay, the one exception to all of this is sailing Downwind. At this point of sail, you are catching the wind to push you along. In every other point of sail, you are using your sail like an airplane wing to create lift and pull you through the water.
Want some dry land practice? Check out this Ocean Racing Simulator. Try to set the sails at a position and drive the boat as fast as you can. Watch the knot meter to see how fast you are going. Now go downwind, then upwind and compare your speeds...which is faster?
See you on the water!
Captain Rob