From a a financial standpoint, both AP classes, and taking college level courses while in high school can safe you money and give you college credits before you begin your college education. Once you get accepted to a school you will need to submit your scores for any AP tests that you have taken. Depending on the score and the school's policy, you may get the course transferred to the equivalent at your college. You will also need to submit a transcript of the college courses you have taken, so that they can be transferred. A transfer credit evaluator at the college will evaluate the courses and determine what the courses will transfer as. Before you register for classes, make sure which classes transferred and what they transferred as, so that you do not register for a courses you have already taken.
Jacqueline recommends the following next steps:
I'm a Transfer Credit Evaluator and Jacqueline's advice is spot on. For the most part, if your scores from the exams for AP, IB or CLEP meet the minimum requirements set by the school - chances are you will be awarded credit for those exams. In my opinion, schools don't really consider one or the other to be "better" since they are all just credits by examination which test your aptitude in the subject area and theoretically should all be testing similar material.
Also as Jacqueline mentioned - when registering for classes in college - be careful not to take courses that you've passed any of the exams for. Colleges do not award duplicate credit. Some schools might have limitations on how many transfer credits you can be awarded, so keep that in mind as well, too.