The Course
Typical sailboat racing is to windward and leeward marks.
Sometimes there are 2 marks, sometimes 3 or more.
A starting line is usually formed between a bouy and race committee boat, or could be between 2 bouys, or a bouy and a fixed object such as the dock.
The course usually runs upwind so that you can have a beat to windward, tacking back and forth.
This is an exciting part of the race, boats have to avoid each other and make progress to windward.
The down wind portion of the race is just as exciting.
Someone can pull behind you and steal your wind, slowing you down so that they can pass you.
Don't feel helpless though, because you can turn around and steal their wind, and pass them.
Starting The Race
You sail around on the leeward side of the starting line trying not to run into each other, and observing the right of way rules.
There are many different flag and signal systems to start a race, by my favorite is: 3 blasts of a horn or whistle at 5 minute warning 2 blasts at the 1 minute warning 1 long blast at the start
It is very important to have the 5 minute warning be exactly 5 minutes from the start horn, there are a number of tactics that require accurate timing for crossing the start line.
One tactic is at the 1 minute warning, sail away from the starting line for 30 seconds, turn and sail for the start line at full speed.
If you do it right, you can cross the line at top speed and have the advantage on the first lap.
Another tactic is to just sit at the start line with no speed, and just before the start horn, haul in your sheets and take off.
The most important thing is to stay near the starting line for the start.
The further away you are when the horn goes off, the further you have to catch up to the rest of the pack.
Rounding The Marks
The course is usually sailed counter clockwise.
This is so that when you come around the windward mark, you are on starboard tack which has the right of way.
Many factory racing boats have spinnaker poles molded into their hulls on the starboard side, so that as they come over the mark they can quickly hoist their spinnakers.
You are not permitted to touch the marks as you pass them, if you do, you are required to go around them again.
There are also right of way rules to prevent you from crowding people who are closer to the mark.
There are several configurations for rounding the start/finish line, which is also referred to as the "gate".
Some people prefer to have the gate "closed", so that you can't cross it while racing, you have to round the entire line between laps.
Personally I like to have an "open" gate, so that you cross the line after the lap, and can turn either way to start the next lap.
Right Of Way Rules
US Sailing has a simplified set of rules that are a good place to start.
They might look complicated at first, but after you have raced a couple of times you will see that this set is easy to remember, and will keep you from running into each other.
The Course