Visit local farmers, and ask them about the things they do. Talking with people in the profession can be a useful way to gain insight as well as see if farming is a career you want to pursue.
Decide which sector of agriculture you want to pursue. The different types of farming vary widely. Dairy farming, for example, requires a much larger time and resource commitment than farming apples, but you may find that you have an aptitude for working with animals.
Sign up for a farming opportunity exchange program in your field of interest. For example, World Wide Opportunities on Organic Farms, or WWOOF, is a popular way to learn about organic farming while volunteering your time. Some countries also offer special visa opportunities for those seeking work in agricultural labor. Working on farms is a great way to learn about farming without having to make a substantial commitment of time or money.
Contact an extension service. Many different sectors of farming are served by agricultural extensions that operate through major universities. For example, Cornell University Cooperative Extension provides resources, information and support to farmers in New York State. An extension agent can provide you with specific resources to answer your questions and help develop your understanding of a particular type of farming.
Subscribe to farming magazines. Many of them are free. You will find articles that will teach you about various aspects of farming.
Obtain a job on a farm. Many farmers need hardworking reliable help, which can be a great way to learn about farming while making a little money. You can get a job milking cows or doing fieldwork while still in high school.
Enroll in an agricultural course or degree. A formal education can be very helpful in many areas of farming, from crop management to animal nutrition.
Seek a position as a farm manager. This will allow you to make decisions and learn from your mistakes without having to make the substantial commitment and investment in your own farm. Generally, only large farms require enough labor to need a manager.
Run your own farm. It is generally best to start with a small operation and build it up as you gain more experience and feel more comfortable with the process.