The best thing you can do is get an internship. You get first hand experience and you will learn a lot.
Look for companies with a good finance department and write them an email explaining what you are looking for - even if they aren't actively looking for an intern they may be open to the extra help (since you will be volunteering your time a lot of companies would appreciate the extra [unpaid] help)
Plus a lot of times companies will hire interns after the internship is over/after you finish school. Even if they don't hire you after the internship you can get a great letter of recommendation.