The following are a basic list of common terms that you may encounter if you're new to boating. Knowing these terms can help in the ordering of parts, and will make you look cooler with your family and friends.
Bow
This is the forward most part of the boat.
Stern
The rear of the boat.
Port
Facing forward, port is on your left.
Starboard
Starboard, or stbd for short, is on the right side of the boat if you're facing forward.
Forward
Anything near, or toward the front of the boat is considered to be forward.
Aft
The opposite of forward, anything near or toward the stern is considered aft.
Helm
The helm is wherever your boat is steered from. When driving, the captain is said to be "at the helm".
Transom
The transom is the rear end of the boat. If you have an outboard engine, it hangs on the transom. An I/O has a hole in the transom to accommodate the drive system.
Gunwale
This is usually shortened to gunnel. It is considered to be the sidewalls of your boat, as seen from inside the boat. Essentially, from the floor of the boat to the top of the rail is the gunnel.
Freeboard
This is considered to be the distance from the water to the top of the gunwale (side of the boat).