It is a big, big jump to move from employee to self-employed; not so much because the driving is any different, but because of the many business aspects of the work. You are wise to ask questions. ATBS is a large company that serves thousands of truckers with tax preparation. They have some good business education resources that you may find helpful.
OOIDA, is a professional organization that serves owner-operators. They have a lot of good resources also. Join OOIDA, then give them a call and ask them your questions. Ask especially for the names of books or seminars that will help you successfully make the transition.
The learning curve is steep but once you figure out how to be successfully self-employed, the benefits make the effort you put into learning this way of life well worth the trouble.