Before you go into a casino you should gather every piece of information possible and understand it. Order gambling books, read magazines (there are even magazines on particular games). Surf the internet for more information. Just get smart and professional on a subject. Never handle anything as a beginner (so others might even see and take advantage of it). Always handle everything as a pro. It's as easy as this.

Search the internet for the keywords about your game, strategy, casino or whatever. The best results for your keywords are probably delivered by the Google search engine.

Watch others playing the game you are interested in first to gain some insights. Maybe you can notice some professional gamblers at the table and watch them for a while to see when and where they are betting. Always feel free to ask the dealers. They are getting paid for answering your questions in a polite way. Get information on current table limits and all the things important for your game. At the tables where it is allowed to talk with other players, ask them too if you like. 
There are online casinos which provide public multiplayer games where you can chat with others as well. All Bossmedia casinos for example. (See list of Bossmedia casinos) 

Dealer: Makes change, takes and gives chips, and deals the cards, controls the dice, or spins the wheel. Deals 40 min. and breaks 20 min. over an 8-hour period.
Keno Runner: solicits and shuttles keno tickets from the casino area to the keno lounge and delivers results and payments to winning players.
Change Person: Assigned to the slot area to provide change and, on big payouts, cash for award winners. Most casino employees start out as change personnel.
Floor Man: Supervises a group of tables within the gambling pit. Extends credits, gives comps, settles disputes, and bars players. The floor man answers to the pit boss.
Pit Boss: Supervisor in charge of the entire pit area, including blackjack tables, roulette, craps, and the Big 6 wheel games. Final authority in any dispute. Approves credit for high rollers. Supervises all floor men.
Shift Supervisor: Takes full responsibility for all action in the casino during his 8-hour shift. Reports to the casino manager. Oversees big payoffs at the slots or keno. Ensures that enough staff are available for all the games.
Casino Manager: Responsible for entire casino operation. Key manager for all gaming. Sets the tone of the casino. Decides what rules are used for the games, how many tables there are, and how the pits are laid out.
General Manager: Head of the organization. May even be owner. makes the major decisions about everything. Usually responsible for the restaurant, the entertainment, and the hotel as well.
Eye-in-the-sky: Hidden cameras suspended in bubbles on the ceiling of the casino. Observe and record all action throughout the casino floor, looking for cheating players and cheating employees.
Outside Man: Works undercover and looks for cheats, dishonest casino employees and card counters. Usually an outside man is a former card counter or law enforcement officer.
Gaming Board: Government agency that issues licenses and governs all gaming and oversees enforcement of rules and regulations as applied to casinos. The principal regulatory body in the US is the Gaming Commission.

Start to play in the casinos quite times. The limits are lower, you have more time to ask casino personnel and to get more familiar with everything. 

You should start with small bets while learning and gaining experience. Choose the lowest-stake tables and bet as little as you are able to. After having won some wagers move up in scale and on to the more expensive tables.