When to cut baby hair? Usually people do it on first month? 4th month or 1 year old? Or do we have to cut on 1 month, 4th month and 1 year? Heard it's good to shave it all and baby hair will be fuller when they grow up? Pardon my ignorant ... :)

It depends what you believe in. Most shave off the hair at one month some around 3-4 months when baby starts to drop hair. I think the part about thicker hair if shave off is bullshit. My girl had her hair shaved off at one month. Her hair is still thin and wispy and light brown. It all depends on genes.