Addy Osmani introduces backbone.js as one part of the toolkit for building mobile JavaScript web applications. Backbone is an MVC-like framework to structure your application, simplifies server-side persistence, decouples the DOM from data, succinctly separates apps into Models, views and routers and provides synchronisation between DOM, model and collections.
Remy Sharp dissects a piece of jQuery code pointing out the red flags. Each flag is taken in turn, explained and shown how to correct. Takes into account context and the flexibility of jQuery
A useful overview / introduction of the jQuery library, covering using selectors and XPath expressions to target specific elements in a document, simple Ajax requests, the basic animations available, restructuring a document, creating jQuery plugins.