I'm assuming you have some user stories, and requirements already. I like to create a rudimentary domain model (basically a class diagram), perhaps not having ALL of the fields that everything will contain, but enough to get a general idea of how everything is connected, inheritance hierarchies, and what everything is.
As for coding, I like to start with a single resource, and get some basic functionality built up around it. I don't generally hook it up to a DB at this point, I'm using a pretty simple DAO that stuffs things into a collection of domain objects.
Next, I add a handful of minor connected resources, and start building up the various links between them. At this point, I've got a few domain objects in place, but might not have built up all the fields and stuff they need. Just a few important fields that are enough to differentiate between instances of the objects and link a handful of them together.
At this point, I try to flesh out the domain objects I have with fields and behaviors, and add the required bits to the view(s) to make those features usable. Then, I get some sort of real usable persistence working, set up validation, and make the views pretty.
Refine what you've got, then iterate to cover the remainder of your model.