Cruising is a most convenient way to visit a lot of destinations within a short period while enjoying a global experience, particularly in areas like the Mediterranean. A cruise ship is an all-inclusive resort where the accommodating staff will make it easy for you to have a wonderful vacation. But be aware of extra fees and costs that can sneak in if you have not done some homework.

Join cruisecritic.com before you book or sail. It's a comprehensive re for information about every component of a trip and the community forums are great ways to find out about the good – and not so good – parts of itineraries. Once you've booked your trip, sign up for your departure's Roll Call where you'll get information about what's going on and who's traveling, and find opportunities to share costs by joining in on port-of-call excursions that fellow passengers are looking to arrange.

Work with a travel professional to book your trip. Even if you're an experienced virtual traveler online, a cruise specialist from a large travel agency will provide valuable help in booking your trip, particularly if you're a first-timer. At Liberty Travel, for instance, the agent will usually have, at her fingertips, numerous deals, rebates, res and recommendations that make it easy to put together a trip package. She can coordinate flights, book your pre-cruise hotel and airport-to-hotel transportation, as well as present options for departures and types of cruise lines that take your budget into account. Without an agent, it might not occur to you to arrive at the departure destination a day or two before (if you miss your cruise departure because of a flight delay, you'll need to get to the next port on your own). Often you can select from several booking perks (Celebrity Cruises, for instances, has been known to offer pre-paid tips, an onboard room credit and a beverage allowance). You may opt to buy trip cancellation insurance; it can be often done as part of your package under the umbrella services of your travel agency.

* They have better communication with your cruise line to confirm or change arrangements. You'll never have to sit on hold while trying to get through to customer service.

* There is always someone there 24/7 to help you before, during and after your trip. If you're not happy with your pre-cruise hotel room, for instance, your agent is probably going to be able to get you moved. You won't have to be the one doing the complaining.

* The agency is your advocate for making things right with any portion of your trip. For example, suppose that when you're back home, you discover that one of your shipboard perks had not been applied to your account correctly and you've been charged. You can try going through the cruise line customer service but will probably get much better service through your travel agent who has the leverage of multiple possible future bookings. A couple of hundred dollars overcharge on your credit card is an unhappy way to end a vacation.

Your ship's extra-fee specialty restaurants – some ships have as many as seven – may be great, but don't feel the need to try each one of them. If you're from a big city or travel a lot and dine out often, the specialty restaurants on the ship may not be that much of a treat. Bypass the main dining room too often and you risk missing some of the specials that the chefs there have planned. However, if you're into the particular cuisine, want to experience a Brazilian churrascaria, or are celebrating a special occasion, the extra costs of specialty dining are indeed worth it.

• Check the community forums on cruisecritic.com to research popular on-board restaurants and make a pre-cruise reservation if something really catches your eye. Otherwise, wait until you are onboard to check out menus and fees.

• Be sure to check out the Asian and Indian food at the buffet. Cruise kitchen staff often hail from Asia and India and you'll be treated to their delicious home cooking.

Do the math on beverage packages. Cruise lines, like restaurants and bars, make money on alcohol (and water and soda and coffee...). While some cruises (Viking River Tours, for instance) tout unlimited beer and wine with their dining, most cruise lines charge by the drink and offset that with an assortment of beverage packages that can be purchased to provide an easy, and sometimes more affordable way to have the sodas, juices, cocktails and wine that you want.

You'll need to ask yourself some questions, though, to find out how often you'll take advantage of the package. And keep in mind, that if one of you purchases a package, all travelers with you, including kids, will need to be part of the package. Will you want to have frozen drinks by the pool or wine with dinner? Will you sit at the frozen martini bar for a nightcap?

Before you sail, consider purchasing a non-alcoholic package that includes fresh juice, brewed coffee drinks, bottled and sparkling water, and hot and iced drinks all day long. During shore-excursions, you may find that you can enjoy better-priced, delicious local Italian and Greek wines from the restaurants you visit.

Some cruise lines pro-rate their packages up until a few days before the cruise ends, so you can get a reduced price on one if you do decide to purchase it on board. You just may not know until you're underway. And note: Since your room key card works as a ship credit card, always know where it is. If it gets lost, someone else could charge up a lot of drinks with it. If you're traveling with kids, advises travel guru Wendy Perrin, don't activate your child's room key for that reason. Check out Wendy's excellent advice for your trip.

Staying in touch at sea is a challenge at best. In a nutshell, phone use and internet connections will be spotty as your ship moves from port to port. Wi-fi access may require purchasing a fee-for-minutes package from the ship to gain access to their communication network. With onboard wi-fi, you may find yourself competing with around 3,000 other passengers plus crew for access, which can make it difficult to get a sustained signal for using your iPad well. You can try taking advantage of port stops to find a hotspot on shore. Ask a ship employee where they go to log on, and they'll point you to the cafe or port store that will provide you with log-on info, usually for no cost. But this is not the best time to do your online banking or anything else where you'd prefer a secure line.

For cell phone use, get information from your carrier and be prepared to purchase an onboard-phone package for your ship. Not all carriers will work on every ship; check with your cruise line.

Pick and choose your shore excursions. The ship will make it very convenient to purchase and take excursions at every port of call and a big advantage of this is that all arrangements are made for you and the ship is responsible for getting you to and from your excursion.

• Popular tours may sell out in advance, so reserve pre-cruise, keeping in mind that you can cancel (usually without penalty) the day before the excursion. You may make your own arrangements too, with private tour companies that may charge less, but you'll need to make sure you get back to your ship before departure time – otherwise you'll need to arrange and pay for transportation to the next port of call.

• Do you always need to pre-arrange? No. Do some research: Check the ship's website, cruisecritic.com, and viator.com – and you will find that many ports are close to town and you can just walk off your ship for attractions, restaurants and shops. Your ship will issue a daily bulletin that gives local transportation information too, so if you want to explore a little more, you'll have some less-expensive options.

If you're traveling overseas, carry a credit card that charges no transaction fees for foreign purchases or currency conversion. (See Gold Vs Platinum AmExCard and Chase Sapphire Preferred Vs AmEx Platinum?). Visa and MasterCard are more widely accepted overseas than American Express. Newer cards have a chip feature to deter fraud, and many offer extra points when used for travel and dining. If you make at least one foreign trip per year, you may find that using your card year-round will offset the higher annual membership fee.

Wise advice from travel pros and cruise veterans can smooth your way, help you get what you paid for and let you dodge a few beginners' mistakes.