CHARLOTTE, N.C. – If you’re asked you buy a coffee machine for the offensive line meeting room, do it. If you have a bad first game, forget it. If you get asked to take a drug test, remember you have a good-paying job.

This is just some of the advice you’ll read about in “The Rookie Handbook: How to Survive the First Season in the NFL.’’

The book was co-written by Carolina Panthers Pro Bowl center Ryan Kalil and former offensive line teammates Jordan Gross and Geoff Hangartner.

It hits the street on Sept. 6, just in time for the NFL season.

Here is an open letter the three wrote to all rookies to promote the book:

We already know what you are thinking ... not another piece of unsolicited advice from some crusty veteran or has-been former player. We get it. At this point you have likely had more unwanted words of wisdom than you can possibly comprehend. In fact, you have probably stopped listening, tuned out the noise, and decided you already know what you are doing. You are not alone; most rookies are the same way. We were too. Our hope is that you keep an open mind and at least consider our advice.

Why should you listen to us? All three of us were dumb rookies once too. We all ended up having successful careers with over 30 years of combined NFL experience. But that is not to say we didn’t make some mistakes along the way, especially in our first years. Between us, we were overly sensitive, had a hard time fully understanding our rookie responsibilities, got bad nicknames, had to learn to deal with rough performances on the field, and learned some interesting lessons off the field. Luckily, we were able to overcome our mistakes, and because we want to help you to avoid our stupid rookie errors, we wrote a book, ‘The Rookie Handbook: How to Survive the First Season in the NFL.’ There are words, sentences, and even paragraphs in the book, but we also made sure to add lots of drawings and diagrams since we know that not all of you were on the dean’s list in college. Reading our book will not guarantee that you become an All-Pro, a starter, or even make the team, but hopefully it will give you some guidance on how to make the most of the amazing opportunity to play professional football.

Panthers center Ryan Kalill and two former Carolina O-line teammates have written a book that offers rookies such sage advice as, "Buy the damn coffee machine." David Newton/ESPN.com

Here are some tips to get you started:

Know your role: Always remember that you are a rookie, the low man on the totem pole. Whether you are a rookie of the year candidate or the 53rd man on the roster, you will be asked to perform a number of duties, including but not limited to carrying pads, buying lunches, bringing donuts, and stocking the meeting room with snacks and drinks. Fulfill these roles to the best of your ability knowing that next year there will be a new class of rookies that has to put a fresh towel out on your chair after practice. Don’t be like Jordan Gross who, based on advice from his friend and fiery college teammate Steve Smith, refused to buy a coffee machine for the offensive line meeting room, causing a major rift amongst his fellow linemen, almost single-handedly ruining the camaraderie of his position group. Performing your rookie duties well will enhance the experience for veterans and rookies alike. Just buy the damn coffee machine!

One snap and clear: No matter how successful you were in college, there will be tough plays and days in the NFL. Ryan Kalil has become a perennial Pro Bowl center, but you wouldn’t know that based on his first start as a rookie. Playing right guard, he had a rough afternoon against the Texans, giving up a couple (maybe even a few) sacks. Fortunately, Ryan knew that the best way forward was to analyze his mistakes, learn from them, then forget about it. Dwelling on past performances, good or bad, will not help you perform well in the future. In the words of our great line coach John Matsko, “One snap and clear, stud.”

Be flexible: Most of you were outstanding players in college, likely specializing in one position on either offense or defense. There aren’t many guys that get that luxury in the pros. It would be a good idea to learn to play as many positions and fill as many roles as possible if you want to stick in the NFL. Geoff Hangartner was lucky to have been given this piece of advice early in his rookie campaign because he wasn’t going to make the team playing only one position. Learning to play center, guard, field goal protection, kickoff return, and backup long snapper (hence becoming a Swiss Army lineman) allowed him to stay in the NFL until he finally became a full-time starter in his fifth season. It probably also gained him an extra year at the end of his career. It’s widely known in the NFL that “the more you can do, the harder it is to get rid of you.”

Act like an adult: In case you haven’t figured it out yet, you are now officially a grown up. You will have a 401k, a severance package, health benefits, and a union card. You are going to need a financial adviser, an insurance agent, and a dentist. You will also have to pay your own utility bills, buy a car (don’t go crazy on this one), and maybe even take out a mortgage. Your job has a dress code, you have company Christmas parties, and you will get drug tested. You receive bonuses, get fined, get raises and can even get fired. Yes, my friend, being in the NFL is a job. Don’t ever forget it!!!

Enjoy the journey: Most importantly, have fun along the way. Enjoy every day ... even the tough ones. Remember, you are living your dream and being paid handsomely to play a game we all love. Have fun in the locker room, it is such a unique place. Some of the best people we have ever met have been teammates, and the three of us forged lifelong friendships based on our time together playing football. There are guys from all different backgrounds shoved into a room together. Put your phone down and engage your teammates. Real life is better than Instagram. Trust us. You will be surprised how much you have in common with these guys. Their stories of triumph and perseverance will inspire you. And we guarantee you will learn some amazing jokes. You will witness, and fall victim to, some hilarious pranks. Make sure to have thick skin. Whining and getting upset when you are the butt of the joke will only make it worse.

Remember, you have two ears and one mouth. Listen twice as much as you speak. You’ll probably learn something. Use all the resources you have at your disposal (including The Rookie Handbook) to do your job to the best of your ability. You only get one shot at this thing ... don’t screw it up.

We wish you nothing but the best.