On a related note, if anybody is looking for a mature source but with a substantially worse UI, I've been referencing the Library of Free Data Models  for years.
Just providing a schema and a name for the pattern is a way to get started, but it doesn't tell me why this pattern is a good fit for what I'm trying to achieve.
Change the price of a product then calculate last months revenue.
I'd also like to see a brief about what the pattern is trying to solve and why it is the way it is. I've used patterns for sortable hierarchical categories before which is more complex than a parent/position relationship. That would take a bit of explaining with regards to querying, sorting, inserting, removing records.
But all in all, I like it. Nice clean UI and can see it growing.
David Hay's Enterprise Model Patterns (and his earlier ones). This is a beast of a book, but has some great patterns.
Len Silverston's Data Model Resource Book Vols. 1, 2, 3. Good case studies by industry in the last 2 books.
Michael Blaha's Patterns of Data Modeling . This one has some interesting temporal, graph, and tree models.
Martin Fowler's Analysis Patterns. This one skims some of the other patterns, but gives accounting a solid treatment.
They are all well-rated on Amazon and I have read them and they are all very good. A few are available on Safari too.
EDIT: Noticed you also use jsPlumb. How was your experience with that and did you ever consider other options? I had a few smaller projects that used jsPlumb, but it seemed pretty limiting once my diagrams needed a little more functionality.
jsPlumb is cool, but the API is terrible. I don't like. I will rewrite all the connections.