Peterson's Master the ASVAB w/CD is the essential guidebook for anyone looking to jump-start a military career. It provides four full-length practice tests, including a diagnostic test, along with profiles of more than 125 military careers. This guide also provides extensive detail on the AFQT sections (Armed Forces Qualification Test, comprised of two verbal and two math sections) and coverage of all ASVAB test subjects, with dedicated sections for each subtest. The CD is loaded with additional practice tests and a vocabulary builder.
If you're looking to jump-start your military career, then this study guide for taking the ASVAB, complete with CD, is exactly what you need.