d3.js has a steep learning curve so it is a good idea to read several tutorials before diving in and trying to create your own visualization from scratch.
The Hitchhiker’s Guide to d3.js is a wonderfully-written resource that explains the context for how d3.js works and how all the pieces can be used to create your desired visualizations.
d3.js first steps contains the code and markup for building your first d3.js visual.
Reusable and extendable d3 charts is a natural extension of the d3 plugin post. It shows how to reuse visualization code between multiple visuals.
Visualizing Movement Data - Part I provides a detailed example of how to draw a complex visualization.
This Fantasy Map Generator is such a cool example of what d3.js can procedurally generate based on a set of inputs.
Argyle in d3? Oh yes, the library can do that, and here is the code to prove it.
Resize to Scale with d3.js gives code for a render function that adjusts the size of the viewing window based on the parent element for the visualization.