Find out when the school to which you are applying is giving the HSPT. Most schools typically only give the test once a year.
Register for the test.
Study for the test. There are books, flashcards and tutors available online through sites such as flashcardsecrets.com and studyguidezone.com. Kaplan is a highly recognized organization that offers pre-tests and study guides.
Take as many pre-tests as you can afford. Practice helps and will familiarize you with the various sections and how they are arranged.
Make sure the test results are included in all your transcripts because schools use results from the test to make admissions decisions, to place you in appropriate classes, as well as to determine scholarship awards.