Crew- Your crew grows by adding people in the invite section, or by receiving invites from other players. Your crew size determines how many people will "race with you" when you are racing someone. For each level you can have 10 people from your crew "race" (up to lvl. 50, then 2 per lvl.) This doesn't mean that the crew members are actually involved, or that they will be aware of their involvement. It's just a number. Each crew member racing can have one car, one performance part, and one illegal mod.
Races- Race winners are determined by crew size and weapon strength. If you race someone in your own crew, you may upset them, especially if you are a higher level than them. Attacking lower levels than yourself is mostly frowned upon, but many of the people on the legends list for races are on the list because they attacked lower levels, usually from their own crew because they are easy to find.
Some people also go around racing people for money at the lower levels. Once they find someone with a lot of money, they take as much as they can, racing multiple times in a row. This is called farming.
Sometimes, members of your own crew will ask people to race them. This is because lower levels will lose and get them experience so they can level up faster. Make sure that if you help someone out in this way, race them, don't dent them. Dents don't help them gain experience, it just damages their ride.
Leveling up- Leveling up takes time. You level up by earning experience through races and jobs. It may seem very tempting to buy respect points right away. There is nothing wrong with supporting the game through buying respect points, just don't do it at a low level. If you can hold out until you level up, the points will get you a lot further. Don't add to your boost or handling (attack and defense) strength, it only affects you, not your whole crew. You can always add some at higher levels, but at first, other stats are more important than making such a small change in your boost or handling.
Bulletin board- The bulletin board may seem to look like spam, but most likely is not. People post other players friend codes so that their crew will add them or post them. If you want someone to post your code to their crew, just ask them to trade posts and leave your code. They will send you their code if they want to trade, so post their code to your crew and they will do the same (usually).
Try to trade posts with people who have big crews, this will get you the most invites. There is no program to copy and paste codes unless you have a jailbroken phone. If you plan on trading posts, consider making a daily post trade. Save the peoples codes in your notes app on you phone for easy copy/paste every day. You post them everyday and they do the same for you. Usually, daily posters expect to be trading multiple posts per day (3-10) If you are looking to communicate more with your crew, many people use a free app from the app store called Palringo a.k.a. "Pal".
Comments- You can get older comments through your profile. Comments are a direct way of communicating, as opposed to posting a bulletin and telling your whole crew. You can comment anyone in the game, but remember that this will leave a link to find you later. The only way to get rid of this link is bound to get you in trouble too. To clear the link, someone (not you obviously) has to spam the persons comments. Because comments are limited, sending messages enough will push your message off the list. It will also make the profile owner very mad, and leave a link to the spammer.
Blacklist- The blacklist is like a hitlist. People will pay to blacklist other drivers. When you are on this list there is a bounty on you, so people will be trying to total your ride to get the bounty money. You will be on the list until your ride is totaled. The cost of your bounty is ten times your hourly income.
ATM/Garage- The ATM is of course where you deposit money. This will keep your money safe from other players trying to race you for it. The only catch is that the ATM will take 15% of your deposits. It may seem like a lot, but each race can take away $100,000. If you aren't using your money, put it away. Some say to take the risk and stay away from the ATM, but it just isn't worth it until you are at higher levels and have more money. You must maintain a minimum balance of $2,000 and there is a minimum deposit of $10,000 at first. Money becomes much easier to come by as the game goes on and the jobs pay out higher, but everything becomes more expensive too (and better). The garage is where you go to restore your health. You need money in the ATM to use the garage. The cost of repair increases with level.
Resetting- Resetting your game will erase all progress and items besides your crew. You will never lose your crew in the game unless someone deletes you, which won't happen unless you spam or annoy them. If you have items from redeem codes or other special items (illegal mods), they will be lost. You can't get them back since the redeem codes and special items can be used only once, unless they are obtained through a job. The only way to change your class is to reset (i.e.- from muscle to import). Changing classes gets you healed, refueled, or payed 10% faster.