You are asking good questions but you will need a LOT more educating your self before you become a contractor.
A "bond" is an assurance that you will complete the job as bid, specified, on time and other contractual agreements. A bond will cost you an additional 3 to 10% payable to a bonding company. You will have to show the bonding company that you have enough assets to cover the bond should you fail the terms of the contract AND have a proven contracting record of meeting those term as a contractor.
"Net 60" mean you will be paid 60 days from your invoice. Which in my opinion is BS. I demand Net 30 or I do not enter into a contract. As a contractor you do not receive payroll. You are paid a contracted amount which includes payroll to you and your employees, payroll taxes which the about 7.5% (your employer pays that now. As an employer you will pay it. Also insurance, workers comp, phone/internet, equipment, trucks, tools, repaired, upgrading your equipment, health insurance, attorney fees (you will have attorney fees if you own a business), CPA fees, interest on loans, income taxes, hotel,fuel, and the list goes on.
