Some games allow for FPS reading in the settings. Or you can use a game recorder like Fraps or Dxtory to also see your FPS. This does not need to be recording to see your FPS

Anything from 60+ fps is good. However, it depends on your monitor. Example, is you have a 60Hz monitor, then 60+ fps will look smooth. If you, however, have a 120Hz monitor, then 120+ fps will also be better. Im not 100% certain on this so if anyone can clarify that will be great.

As Editions said, Fraps is a good indicator as it doesn't hit your CPU very hard. personally I think that 30fps is sufficient but the magic number is considered 60fps. The Xbox One/PS4 currently run most games at 30fps. Films are produced to 24fps. Also as Editions said, if your monitor is capped to 30 refresh rate, crank up the settings until you get to thirty, if your monitor is capped to 60 refresh rate, crank up the settings until you get to sixty.

well i run every game on ultra i was just wanting to see what fps i was getting and i was runnning 60fps with a 60 hrz refres rate monitor.