Here is a general resource for looking at the developmental stages that young children go through as they grow. Scholastic.com has developed these charts that outline the timeline of developmental progress usually made at different ages. There are charts that show the development of motor skills, play, creative thinking, cognitive skills, math, literacy and more. However, I think it's important to remember that not all children develop at the same rate, and there can always be exceptions to these guidelines, especially in the first years of life.
It's absolutely important for parents, caretakers and teachers to understand where their kids are at developmentally, as well as where they should be that, so that they can help facilitate healthy growth and development with appropriate activities. But we need to be careful not to assume that just because children are a certain age, that they are in a particular stage of development.
Every child is an individual- a unique, amazing human being. We need to get to know them and their development on an individual basis.
General charts and guidelines can be helpful in guiding our interactions with young children, and determining if there is significant developmental delay. Just don't forget that age is not the only indicator of development. When examining our instructional approaches and interactions, we need to consider the whole child: their experiences, their abilities, and their current stage of development- even if that stage is different than what's expected for their age.