Any suggestions on security besides the obvious alarm system, security cages for A/C & HVAC, etc.  

@James Williams   The very best way to answer all your questions is to Simply waltz into your nearest C 21 or Keller Williams or Re max office and speak to the recruiting broker tell them that you want to pursue a career in RE and they will answer all your questions help you get started with the education etc etc. 

@James Tsuffis , I apologize for the late respond, just came back to the US after visiting family abroad.It is extremely challenging (trying to keep it on the positive side...) to find a decent 4-plex in B-C area around Los Angeles or better areas of San Fernando Valley, with my low-newbie budget, and still use it as the main residence.

(Usually designated by a "C" tacked onto the end of the district name, for example "R-4-C."

This cost saving measure as supported in the Housing Assistance Payment (HAP) contract, Part B, Section 6(c) , which allows the PHA to re-determine the reasonable rent at any time in accordance with HUD requirements."

@Elizabeth C. 

The MLS has it with the address and lists it as Unit C but the description says it's 4 units.

John owns an LLC with 4 properties (properties A, B, C, and D) under the LLCs name.

The lien priority on this one looks like this:Lien A (foreclosing party)Lien B (second in priority, third in time)Lien C (third in priority, second in time)C signed a subordination agreement with B at the time of B's DOT, so B is third in time but second in priority.

Richard C. that is the game of real estate investing.