also, is the probate procedure a very long process?

Do's, Don't procedures, forms, anything would be helpful.  

On the HUD website it says only that: At least 80 percent of the units must have at least one occupant who is 55 years of age or older; andThe facility or community must publish and adhere to policies and procedures that demonstrate the intent to operate as "55 or older" housing; andThe facility or community must comply with HUD's regulatory requirements for age verification of residentsThis all seems a bit too easy to me, but can't really find step-by-step directions anywhere to do this.

That business is comprised of policies, procedures, structure and laws, many many laws.

Not every city implement a procedure as yet.

If it sits on it's own land, but not on a permanent foundation, then find the value of the land through the normal real estate comps procedures, and find the value of the home's "blue book value" and add together.

We are looking at a duplex on Pasadena, CA. The front unit is vacant and the back unit has a tenant who has been there for 9+ years (month-to-month rent agreement). The back unit is in bad shape (no immediate danger, ...

I have the owners contact information, so I was wondering if there is such a procedure for mailing something out, and letting them know that you are interested in taking over the loan, providing they can provide some financial information about the property.

If homeowner, then they have rules like premiums not being repaid, long redemption periods, low rates, difficult foreclosure procedures.

Success is an individual thing measured by individual metrics.The wealth-building procedure you describe is the one outlined in The Automatic Millionaire by David Bach.