How do Real Estate Agents Search for Properties?

[Salvador Santolucito]

I am about to put my property up for rent and have a question about using a real estate agent vs. doing it myself.

• When a tenant uses a real estate agent to find a rental house, what does the real estate agent use to search for houses? 
• Does the real estate agent just use MLS?
• If I advertise my property on all the DIY sites (Zillow, Trulia, etc.), will a real estate agent representing a tenant find it?
• Do the homes on those DIY sites get propagated into whatever tool the real estate agents use?

Thanks,

Sal