Inspirational, evidence-backed ideas to support your teaching. This website includes approaches, to include great books, to support early mathematicians. 

A UK site providing guidance on teaching maths to children from birth to 7. 

Designed to support teaching from 3-7 years, this is a free to use website but you do need to sign up. Although American, it provides some very useful resources. Do pay particular attention to the learning trajectories themselves - they show the steps that children typically go through in developing their understanding of a concept. If a child is struggling to understand a concept that you're teaching, you can look at the preceding steps and see what the specific issue might be and how you can tackle it.