Be Advised: Classified, FOUO, and PII Content is Not Permitted
The current "go-to" book is "A Practical Guide to SysML" by Friedenthal, Moore, Steiner 3rd Edition
"SysML Distilled" by Delligatti is much shorter, thus a quicker introduction, and easier to keep as a desk reference, however it leaves out some critical aspects of SysML that are covered in "A Practical Guide to SysML" for practicing SysML modelers.
There are discount codes from the OCSMP website for SysML Distilled and Practical Guide (Friedenthal), and a couple others.
http://www.omg.org/ocsmp/study-material.htm
PAX has access to a couple of hard copies of these books through the tech library, then search SysML
That link only works on NMCI and access to the on-line catalog is restricted to Civilian and Military employees.
https://myteam.navair.navy.mil/wd/40/techlib/SitePages/Our%20Catalog.aspx
Contractors can only borrow material through their government sponsor by having them write a contractor letter indicating contract number, need-to-know and length of access. Full policy can be acquired by contacting the library.
PAX employees also have access to digital versions of some of these books, please contact the library for information on how access them. It is moderately easy.