Golf Etiquette 101
Golf etiquette really doesn't need to be intimidating for new golfers. Most of golf etiquette is just politeness and common sense and for the rest, you can peruse the points below.

Avoid slow play (When your group is not keeping up with the pace of play of the group in front of you):
Walk at a reasonable speed between shots.
Begin planning your next shot as you approach the ball by studying the strength and direction of the wind.
When you reach your ball, check the lie, select your club, visualize your swing and shot, and then play your shot.
From the time you select your club until you actually hit your shot, you should take no more than 30 to 45 seconds.
If you aren't ready to play when it is your turn, encourage one of your fellow players to play.
Maintain the course:
Replace your divots - turf tends to explode on impact, making it difficult, if not impossible, to replace the divot. In this case, you have two options: (i) you can use the toe of your shoe to kick in the turf around the edges of the divot; (ii) many courses often put containers of a soil/seed mixture on their carts and tees. If this is the case, simply fill in the divot with the mixture.
Heading to "the Beach": Bring a rake into the sand trap with you; you should always enter the bunker from the low side at a point nearest to the ball; whenever possible, avoid walking on the steep face of a bunker; after hitting your shot, rake the area you played from, as well as all your footprints and any others within reach; rakes should be left either in or nearby the bunker.
It is important to repair any pitch marks or indentations caused by the ball hitting the green: using a tee, knife, key or repair tool, repair the mark by working the edges towards the center, without lifting the center of the mark; don't tear the grass; finish by smoothing the area with a club or your foot - try to get the area smooth enough to putt over. While the Rules of Golf allow you to repair pitch marks on your putting line, you cannot repair spike marks on your putting line until after you have putted.
On the green, remember:
Don't step on your fellow players putting lines -- the imaginary line that connects the ball to the hole.
If your ball is on a player's line, volunteer to mark the ball.
If you're ball is not furthest from the cup: mark your ball, either with a plastic marker or a small, thin, dark coin such as an old penny; after you have marked your ball, place your putter down at a 90-degree angle with the heel touching your marker; move the marker from the heel to the toe of your putter; reverse the procedure to return the ball to its original position.
Do not stand where you might distract a fellow player and don't move.
Don't make any noise when your fellow player is preparing to putt.
If you don't have a caddie and are asked to tend the flagstick, make sure you aren't standing on anyone's line; hold the flagstick at arm's length so the flag doesn't flutter in the breeze, and make sure your shadow doesn't fall across the hole or line; loosen the bottom of the flagstick so it doesn't stick when you try and remove it by pulling it straight up after the other player has putted; the flagstick should be removed right after the player has hit the ball -If you lay down the flagstick, lay it off the green to prevent doing any damage to the green.
Generally, the player closest to the hole will tend the flagstick.
After everyone has putted out, immediately walk to the next tee.
Follow these simple guidelines to ensure everyone enjoys the next round together.