Using sites like Zillow, Redfin, and Realtor.com, figuring out deals, and doing your homework well are key steps.

My general understanding of California rentals is that if the building was built prior to 1974 and has 16 units or greater, an on-site property manager is required. 

So far there has been no connection issues with other sites.

You can literally find answers to all of your questions within the confines of this site.

This is a REI site, and I assumed he was talking about property management after construction also assuming he was building potential rentals. 

Lenders will want to know you have a game plan for monitoring a project and being on site frequently especially when it is your first time.

Learn more by setting aims, growing your friend net, and diving into sites like BiggerPockets and other web spots.

Beyond that I could name a ton of tangible site benefits of subscriptions like all the calculators, discounts with partners like Home Depot, the great reports and webinars with tons of data on current markets and trends or the landlord forms just to name a few. 

Be careful with free sites, they only have a couple months of actual data and then project the rest with an algorithm tool.

Welcome to the site @Justin Longacre!