It's quite common for people to not know how to play Craps. I myself did not learn how to play until my friend's bachelor party in April of 2008. Since then, I've enjoyed a few of the greatest gambling nights of my entire life. It seems like I can occasionally do better in Craps than Poker, which seems ridiculous as Poker does take more skill, but I digress.
Here is the basic premise of Craps for anyone who does not know how to play. I'll add in a few tips to get you started and then you can learn the rest as you play at the table.
The First Roll of a New Shooter: The game begins with the designated shooter rolling once. Before that first roll, you'll want to put the minimum bet on the Pass Line. If you can, put the chip over the "P" and you'll get the "Ass Line." How fun is that?!
The roll has three possibilities in regards to your initial bet:
1) 7 or 11 - You win $5 immediately
2) 2, 3, or 12 - You lose your $5 Pass Line bet
3) 4, 5, 6, 8, 9, or 10 - The button is laid on whichever number that is rolled, your $5 stays on the Pass Line.
Assuming Option 3 had come up, and the button was laid, the next goal is to roll the button number BEFORE a 7 is rolled. If a 7 comes first, you lose. If your number comes first, you win. It's that easy.
However, before the next roll you are now able to back up your bet with odds. YOU ALWAYS WANT TO DO THIS!!! All you have to do is put chips in the space behind your Pass Line bet. This is how you make money. Sure, you have the possibility of losing faster because your place more money on the table, but hear me out.
Most Craps tables are 3x-4x-5x max odds tables. This refers to how much money you can put behind the pass line. For example, there are three ways to roll a 4 (1,3) (2,2) (3,1) and there are six ways to roll a 7 (1,6) (2,5) (3,4) (4,3) (5,2) (6,1). This means there is a 2 to 1 chance that you'll roll a 7 before a 4. If you have a $5 bet on the Pass Line to start, you are allowed to put 3x that bet if the button is laid on the 4. Your max bet is $15 behind the initial $5 (risking a total of $20 on the next set of rolls.) If a 4 comes before a 7, you will get even odds on your Pass Line bet ($5) and you win 2:1 odds on the money you back up ($30). So you risked $20, but ended up winning $35. Odds for the different button number are as follows:
4 or 10 - 2:1
5 or 9 - 3:2
6 or 8 - 6:5
Now, one strategy I learned early on, was to just buy either the 6 or 8 if the button is set on 8 or 6. I will never do this ever again. You don't really get the same type odds as a Pass Line bet, so it's not really worth it. You would need to hit that number at least once to just break even. That's not what we're looking for. The solution? Play the Come Line.
The Come Line works the exact same way as the Pass Line, except it starts the initial roll whenever you place the bet. It's a game within a game, if that makes sense.
Essentially, walk up to the Craps table, put the minimum bet on the Pass Line. Once the button is set, bet the maximum behind your original Pass Line Bet. If you'd prefer to not bet that big, then at least match your Pass Line bet with backed up odds. NEVER bet more on the Pass Line than on your odds. I've seen people do that and I think "that person has no idea what they are doing." After that, just wait for your number to come up before a 7. That's pretty much it.
There are a lot of fun bets to make in the middle, but ALL of them are sucker bets. If you're gambling and having a fun time with friends, the middle of the table can be temping, but you'll probably end up wasting more money than you win on the middle of the table.
Hopefully this has been helpful. Please feel free to ask any questions, and I can clear up any confusion. It's an easy enough game to start playing, but tough to know all the in's and out's. Have fun and remember to gamble responsibly.