Baseball is back in Baltimore this week, and not a moment too soon. We can't put winter in our rear-view mirrors fast enough. And here's something that makes the return of the game even sweeter this year: Over the past three seasons, the Orioles have returned to the rank of baseball's elite, which means that Camden Yards has become the place to be once again. If you're anyone who's anyone in these parts, checking out an occasional O's game is pretty much mandatory. But what if you're new to the game, or you've never been to the greatest ballpark in the country, and haven't had the chance to bone up on game etiquette a la Orioles? For the rookies among you, here are a few suggestions on how to enter the Jewel of Camden Street and act like a pro.