The Grip

Simply put the grip is just how you hold the club in your hands. There are three regular grips that golfers choose from, selecting the one that feels most comfortable to you is important, and then sticking with it so you don't have changing variables as you learn.

Single Overlap Grip: (assuming a right handed golfer) The pinky finger on your right hand overlaps with the index fnger on your left hand. The opposite is true for left handed golfers.

Interlock Grip: The same layout as the single finger overlap grip, except that the pinky on your right hand (for righty's left hand for lefties) interlocks with the index finger on the opposite hand.

Baseball Grip: Probably not a difficult one to imagine, basically you're grippping the club shaft like a base ball bat. Without any overlapping or interlocking of fingers. All ten fingers should be touching the grip on the club shaft.

Any one of the grips described above will work well, the key as mentioned is to choose the one that feels right for you and practice using that one.

Posture and Mechanics

How you set the ball in your stance, the flex at your knee, straightening of the back, hip bend, and angle which you maintain thorugh the whole swing. The width of your stance should be approximately shoulder width. Knees should be kept slightly bent to allow small amount of motions, and your back kept straight at about an 80 degree angle.

Be sure you're bending at the hips and not your back, keep your back straight at all times. The angle that your back maintains when you're coming through your follow through should be the same which you started with in your back swing. If you change/move the angle of your back then everything else in your swing mechanics will also change.

Pivot

Manging how your body swing through from your head to your toes, and turning into your swing with your hips is the pivot.

Hands and Arms

Hand and arm relationship or better known as coordination is a very important step to learning the golf swing fundamentals.

Picking out a Target

Where do you want the ball to go? Alignment is an important part of the swing that not everyone pays attention to. If you're aiming for the green, then you should make sure that is where you body is aimed and where it will be facing once you've followed through your swing.

Of course there is a mental aspect to choosing a target as well. If there is a sand or water hazard directly in front of you chances are guess where your ball is going to land. Either at the beach or for a swim in that water hazard. Focus on something ahead, keep your main objective in mind, and ignore hazards treat them as if they're not there.

Mental Aspect

Probably the most important yet the least physical aspect of golf swing fundamentals. Some pros say that upto 90% of their game is mental, you have to be able to get in the right state of mind, visualize the next shot, and also perform all of the above mentioned fundamentals without thinking about them. So practice is what it takes to get them down. Your body will be able to reach a point where it's all natural, and you won't have to think about the next step, until then keep practicing.