I took "Principles of Real Estate" at my local community college.
As I recall, upon passing the class, I was eligible to take the seller's exam.
I'll defer to the professionals on here, but I do know that you need to be very flexible with your hours, and plan on working weekends, hosting open houses, and touring with buyers. The successful brokers and agents I know are available almost 24/7 for their clients. A well-equipped home office, with an above-average fax machine would be most helpful for working from home.