Dumb question but here goes. I was given a Remington 14" chain saw without the manual, There is one black knob (reserviour,tank) and I am guessing that oil goes in it. Bar oil?

BTW, you are correct about the black knob. The bulb on top of the cap is pressed every few minutes to keep the bar lubricated. Press the black bulb in before you cut, placing oil on the bar and chain. When you've cut a bit, or when you notice that you don't see any oil on the bar or chain, it's tome to oil it again. With use, you'll develop a rhythm where the bar never lacks oil. It's hard to say just how often to oil the bar and chain, as it varies with what type of wood you are cutting, whether it is wet or dry, and so on. It is better to over oil than to under oil.
--W/D-- BTW, you are correct about the black knob. The bulb on top of the cap is pressed every few minutes to keep the bar lubricated. Press the black bulb in before you cut, placing oil on the bar and chain. When you've cut a bit, or when you notice that you don't see any oil on the bar or chain, it's tome to oil it again. With use, you'll develop a rhythm where the bar never lacks oil. It's hard to say just how often to oil the bar and chain, as it varies with what type of wood you are cutting, whether it is wet or dry, and so on. It is better to over oil than to under oil. --W/D--