A truck, contractors trailer bed, and locked storage trailer (full of tools) have all been abandoned and left sitting on my property for 5 or 6 months now. What are my rights?

Is this a Commercial property ( like a repair shop) or private residential property?

Have you contacted the owner of the items? Have you given them a deadline to remove the items or you will consider them abandoned? You have to go through that process you can then auction off the items.

Did you have any dealings with the owner of these truck and trailers, or did someone just leave them on your property without asking you if they could do so?