"It is always best to bet the Pass/Come with full odds or as much in odds as you can afford*"
That is the only rule of craps you need to follow. And, it is complete gibberish to anyone who is new to craps, as I was a short time ago. I am still learning. But this is the best system, or as *King Scoblete is fond of saying, you have the best chance of losing the least with this system. Craps may well have the best odds in the casino but the house still has the edge.

I remember a dinner conversation with a business owner/entrpreneur in Atlanta. I had said craps is too intimidating to me. He used a napkin to quickly explain: You put a bet on the Pass Line. If the shooter rolls a 7 or 11 you double your money (nice, 8 out of 36 rolls). If the "point" is made it means the shooter rolled a 4,5,6,8,9,10 and a white hockey puck is put on that number. You immediately lay "odds" on the point. This means you stack up some more chips behind your Pass bet. And you place the equivelant of a Pass bet out in the COME area of the table. If a 4,5,6,8,9,10 is rolled the dealer puts your COME bet on that number and you immediately hand more chips to the dealer who adds them to your bet on that number but at slightly better odds.
That is the system. Lots of nuance to it. But getting the hang of the sequence is the trick. The cool thing is that the dealers immediately recognize what you are doing (it is the only sane system after all). They will help you through the game and remind you if you forget something.
I have stood at the craps table with every number covered earning $8-20 a roll while everyone around me chases after 12's and hard ways. It is a good feeling to fill up that tray in front of you with chips!
Just remember PCFO: Pass/Come Full Odds.
-Dennis Detroit