In looking at how technology is expanding our ability to explore career options, I came across Wikipedia's category of Occupations. It contains hundreds of subcategories of occupations from fashion to computer science.
And these subcategories often lead to more interesting links, such as the list of notable programmers under the computer science listing. One way to learn about a career is to find out about the path other people in your target field took to get where they are now. You can find that through biographies posted online in Wikipedia - such as the list of programmers. You may even come up with some possible informational interviewees.
Of course you have to keep in mind the information is created and edited by many people, some of whom may be biased or unknowledgeable about the subject. Welcome to the internet. You should be familiar enough by now with the Web to exercise a little caution.