If you're interested in staying at a low budget accommodation 'Posada', I advise you to book in advance. The cheaper rooms tend to sell out beforehand, probably due to the small number of budget rooms on the island. Margarita Island is a popular tourist destination, and is mostly dominated by large scale resorts.
I recommend visitors to not only print out the directions to their hotel, but also the telephone number for the establishment. Our taxi driver wasn't too aware of the location of our hotel, and after arriving in the general vicinity, he had to call the owner to get better directions. Thankfully, I had called the owner the day before, so the number was still stored in my recent call log!
If you're arriving by means of air, you have the option of renting a car or hiring a taxi to get to your hotel. When hiring a taxi, I actually recommend using the local drivers who wait for visitors in the airport arrival hall. These drivers will not only offer you a decent price, but will also act as good currency exhangers. They changed my US dollars into Bolivares at the 'Black Market' rate which is 8 Bs for 1 USD, as opposed to the official rate of 4 Bs for 1 USD.
In the event that you didn't bring enough foreign cash with you, and you need to make a withdrawal from the ATM, there are two things to know. The first is that you're going to be charged the official local rate of 4 BS for 1 USD by default. Secondly, most of the bank ATMs on the island don't accept foreign cards. Only Banco Bicentenario accepted my Visa card, but when asked for a 'code' my hotel owner advised me to enter four zeros (0000) and it worked!
If you're staying outside of the Captial of Porlamar, getting a taxi is not as easy as walking into the hotel's parking lot and hiring the first one who calls you. In Juan Griego, we had to ask our hotel owner how to locate a cab. Taxi stands are usually located in the communities, so don't be afraid to ask the locals to point you in the right direction. Also, many taxi drivers cruise around looking for patrons, so you could also just wait outside your hotel's gate until you see a car with a 'Taxi' sign, then flag it down.
It is easy to become carefree when on the island, because of the relaxing atmosphere, but never drop your guard. Two of my friends were scammed when a guy on the street offered to change their USD for local currency. They ended up losing about $50 USD, and never saw it coming. The scammers and pickpockets that you read about in the warnings are real, so always use caution.