:( my 1st turned two on Friday and #2 is due in 11 weeks - you're all putting me off now!!
Seriously though there isn't a 'right time' that suits everyone. For a long time I couldn't even think of having another baby, because I love my 1st child so much and was content with it just being the 3 of us, but then one day it seemed right, and a couple of weeks later I was pregnant - I had imagined it taking longer to get pregnant and therefore having a slightly bigger age gap!!
Depends on the older child too I imagine, my daughter is a very good sleeper, sociable, caring, independant and loves babies, so I'm hoping that will help!