How to ground arduino properly

How to ground Arduino board properly and i am reading analog current vales through CT(current Transformer), and gettign random values. so i see on the internet people says ground the A0.
Kindly suggest how to ground arduino so that i get not random mixed values
at analog pins.
Any help plz.

There is a topic HERE that may help.

You may have to discern the facts a little but mostly it is valid.

Bob.

You cannot measure an A/C waveform ( ie one that goes positive and negative ) with an analog port .
The analog read takes a point measurement which can be anywhere on a waveform .