Through Princeton you are able to prepare for your SAT on your own schedule. There are many ways to sign up please visit http://www.princetonreview.com/college/sat-psat-test-preparation.aspx to review those choices.
You can take a preparation course for the Princeton Review SAT exam at any time. The best thing would be to revise and use the course until you feel confident enough to sit the exam.
Yes, there are several options for online prep courses for the GRE. Kaplan Test Prep offers one such course for $749, and Princeton Review offers their online GRE prep course for $799. Both of those courses are conducted live, with personal instruction provided.
The Princeton Review or McGrawhill
There are many suitable SAT prep courses. Kaplan and The Princeton Review offer courses in SAT prep, but regardless of the course someone takes they should always make sure to do practice tests.
There are several private tutors that offer training. There are also large companies such as Princeton Review and Kaplan, that offer training to students as well.
What does the research show in terms of which PSAT prep classes are best- Kaplan or Princeton?
I can't specifically say which course is most used as there are a huge amount available, however I would recommend taking a course from Princeton Review or Kaplan for online courses as those are the most well known. Source: http://www.ehow.com/how_4995276_gre-prep-courses.html
There are quite a few lsat prep courses you can take. There are Princeton, Kaplan, Blueprint, and Powerscore. According to some people Princeton and Kaplan is a waste of money.
The Princeton Review at www.princetonreview.com offers online GRE prep courses. You can also call them at 888-955-4600 to find local GRE prep courses or tudors.
Harvard, Princeton and of course, Yale.
I really liked the Kaplan and Princeton Review books. I don't recommend Barron's, though.
The best SAT prep in New York City follows the Princeton review system. This can be accessed at www.princetonreview.com and they have several locations throughout the city.