It greatly depends on how much experience you have already, however, we recommend 100-120 hours of study for all 3 parts combined. Each part is a little different.
Part 1 is on individual taxes, so if you have lots of experience doing individual taxes, much of the information will be familiar to you. Maybe you only need to spend 20 hours studying for Part 1.
Part 2 is on business taxes. It has the greatest amount of information to memorize. In general, people are the least familiar with this information, so it takes them longer. You may want to spend 35 - 40 hours on Part 2.
Part 3 is on Ethics, Practice & Procedure. It is generally perceived as the easiest of the 3 exams. It has the least amount of material to learn, and much of it is very familiar to people. You may need to only spend 15 hours studying for Part 3
If you decide that you don't think you will be able to get through all 3 Parts before the end of the testing season, you should also know that Part 1 is the part that changes the most from year to year. If you wanted to buy all 3 Parts now, you could pass Part 1 before the end of the testing season, and still use the Part 2 and Part 3 materials during the next testing season. Part 2 will change some, but not likely enough to mean the difference between passing and not passing. Part 3 will hardly change at all. Also, upon request, we grant discounts to returning customers who want to update their materials. Just email firstname.lastname@example.org and request a returning customer discount coupon.