what type of my baby's hair? how can I take care of it? what best products suitable for it?
I'm not sure what it is at that length, but it looks 3b. The best things to do for young children's hair is to use natural products. SheaMoisture has baby and kids products for washing, and I love styling my cousin's hair with Kinky Curly Knot Today. Both brands have great, harmless ingredients.
It looks like your child has 3b hair. You should definitely start a regimen to maintain the hair and keep it healthy. You can use a number of different brands with the hair: Kinky Curly, SheaMoisture, Carol's Daughter and Bee Mine. If you need help with a daily regimen, check this out: http://www.naturalhairkids.com/basic-regimen/