Most law schools require that prospective law students take the LSAT by December, to apply for the following fall. The LSAC administers the LSAT four times a year, normally on dates in February, June, October and December. Registration deadlines are usually about a month before the date of the test; but testing centers can fill up, so register early if possible to avoid being put on a waiting list. If you miss the deadline completely, you may still be able to register, for an additional $58 late fee. The normal cost of the test is $115.
To register online, follow the "Online Registration" link on this website: www.lsac.org/LSAC.asp?url=lsac/about-the-lsat.asp. You can also register for the LSAT by telephone by calling (215) 968-1001.