Flip Tanedo (along with some of his colleagues) from the US/LHC team has posted an excellent series of tutorials on the Standard Model at the Quantum Diaries blog. Non-mathematical in nature, this series of blog entries systematically delves into some of the deepest mysteries of theoretical physics in an exceptionally accessible manner.
[Note: At some point, the content of the Quantum Diaries blog was moved to a different server. It seems that not all embedded graphics survived this transition. I have, however, updated the links to point to the new location.]
At the core of these tutorials is a series about understanding the Standard Model via Feynman diagrams:
There is also a short series on the importance of symmetry in physics:
And here are some links to a handful of miscellaneous yet fascinating posts which don’t fit into either of those series:
But wait! Flip isn’t the only working physicist out there with excellent tutorials. Here are some by Prof. Matt Strassler of Rutgers University:
[Please note that I’ve been adding links to relevant articles as they have appeared, so don’t be terribly bewildered if you follow a link and find that it is to an article more recent than this post.]