Books, articles, blogs, whatever materials you caught this bug from are no longer applicable, if someone says you, as an individual without having a broker's license can "wholesale" mortgage notes is just blowing smoke in your ear.

I am ready to do any work – such as painting, small repairs, legwork – searching and calling contractors negotiating price, setting appointments, searching internet/county offices for Tax records and such.Right now I am looking for experience on how to look for deals, what is the best way to negotiate prices, what risks are ok to take and what are not, and making contacts with people, learning true costs of materials and labor and other tricks of a trade.I would be willing to put few thousands of my own money but that is depending on situation.

Mario said there's "junk trash, from furniture to construction material.

A builders risk policy removes these exclusions and can add coverage applicable to the rehab, like coverage for materials on site, etc.disclosure - I am familiar with all of the products as I was a State Farm agent many years ago, and rep for all of the companies mentioned above.

What materials make sense?

In addition current opinions as of the date appearing in this material only and are subject to change without notice. 

It is also possible that a contractor may purchase it because s/he would have the skills that decreases the labor and materials cost for this kind of project.

@Adrian Chu I hadn't considered condos that have HOAs, but that makes sense that they would take care of a lot of external repairs.

She gives you reference sheets with pricing that is super low (not accurate) for building materials to use when calculating rehab costs. 

To what quality of materials.