LSAT registration can be done through the Law School Admissions Council website. There are various deadlines for the four test that are administered throughout the year.
You may ask yourself how long should I study for the LSAT. Just about everyone's answer will be different. However, I think that the basic preparation time should be at least three months. There are some people that does it in a month and I say good for them! But I know that I could not do it.
When I took the LSAT test the first time, I intensely prepared for about three weeks. I say intense prepared, because that is when I started taking practice tests. Prior to that, I reviewed information for about two months. I reviewed basic information such as the LSAT testing sections and LSAT strategies.
With preparing for the LSAT a second time, I studied and did practice tests for almost four months. I recommend doing at least 10 previous actual practice tests, before the LSAT.
I took about a dozen actual pretests, meaning real tests that were administered in the past. I took LSAT tests from December 2010 to June 2013.