Here are some useful websites for PEM-related learning, this list is by no means exhaustive and continues to grow...

Don't Forget the Bubbles (blog)

http://dontforgetthebubbles.com

Genetic Syndromes (a useful table reminder of commonly encountered genetic syndromes from DFTB)

PEM EM Morsels (blog)

http://pedemmorsels.com/morsels

Spotting the Sick Child

https://spottingthesickchild.com

Resus.me (blog dedicated to latest evidence)

http://resus.me/category/sickkids

Life in the Fast Lane (access to blogs, calculators, guidelines)

http://lifeinthefastlane.com/resources/pem

EMPEM (useful podcast on latest evidence)

http://empem.org