These are Scott Murray's D3 tutorials (see originals), updated to D3 v7. A note on the updates.

Transitions

Oops! There is no tutorial on transitions yet. Sorry, I realize that was misleading. But I wanted to tell you about two great resources:

First, check out my Eyeo Festival talk on D3 transitions. It’s interactive, silly, and fun. Better than all of the tutorials so far put together. Maybe.

Second, check out my book, which has a whole chapter on transitions, and is actually somewhat readable.

Enjoy!