We must go at least once a year, however, if you have any mortal (serious) sins , you cannot receive Communion until you have had Reconciliation.
I just went two months in a row and it was wonderful. I found I was less nervous and it took less time (since I had less to confess 8) ). I just love how it feels afterwards.
So my recommendation would be to go as often as you can, even if you just have venial sins to confess!