So my wife said I could top off my christmas gift today with a scope of no more than $150. I went to Bass Pro Shops and bought a Nikon ProStaff 3-9x40. The questions I have are-

Is there anything in particular that I need to look for in mounting the scope?

Should I take off my regular optical sights?

Anything else I should know that will make it easier and cheaper to sight the scope in?

Thanks