Any ideas/guidelines/resources on how to introduce and maintain learnings for little minds in the field of Science Technology, Engineering and Maths?

My son is two and a half and play and frenetic fun are permanently at the top of his agenda of course.

I'd like to take him to the Science museum in London (I've heard the basement is where it's at)

Any thoughts on the topics welcomed. I realise there is plenty way to go from 2 1/2 but interested on how to form a foundation.

Thanks!