Travel to the country through which you wish to enter the Amazon rainforest. The two main countries are Ecuador and Brazil, according to Amazon Rainforest.org.
Take a bus or small plane to the Amazon rainforest from Quito, Ecuador, if you chose to travel to Ecuador. Take a flight from Brazil to Manaus or another Amazon city if you chose to travel to Brazil. You can get an international flight to either Sao Paulo, Brazil or Rio de Janeiro, Brazil.
Arrange to travel through the Amazon rainforest by boat. Many small companies and tour groups are available for this service.
Find a boat that will travel through the Amazon tributaries, rather than a passenger ship that stays along the main river. There are thousands of rivers that enter the Amazon River. Navigating these areas, rather than just the main river, will allow you to see more of the wildlife and other sites you came to see. Traveling by motorized canoe is another option for getting to these more remote places.
Find the right type of boat for the trip you want to take. Smaller boats, called "voadeira," take about a dozen people on day trips around many exotic parts of the Amazon. Longer trips can be taken on wooden boats that often carry hundreds of passengers, but that might not go into the more remote places of the rainforest. Foot tours through villages are available on longer trips.