sample.js

dojo.provide("Foo");                    // always first

dojo.require("All.Your.Code.Are");      // always second
dojo.require("Belong.To.Us");

(function(d){                           // optional wrapper / privatizer / closure

    // privates for this module
    var yep = true, 
        nope = false,
        helperUpper = function(str){
            return str.toUpperCase()
        }
    ;
    
    // declarations
    
    dojo.declare("MyTHing", [inheritanceChain], {
    
        member1: "Public members listed first in declcartion",
        anumber: 42,
        etc: "and so on",
        
        // private members, too:
        _test: 1, 
        _test2: 3,
        _test5: "etc",
        
        // begin lifecycle overrides
        postMixInProperties: function(){
            dojo.mixin(this, { something:"random" });
            this.connect(this.domNode, "click", "awesomeFunction");
            this.inherited(arguments);
        },
        // and so on
        
        // begin public class members
        awesomeFunction: function(e){
            this.foobar = this.oneMore("time");
        },
        
        _privateHelperForAwesomeFunction: function(e){
            // should be immediately following the function it helps
        },
        
        anotherAwesomePublicFunction: function(){},
        oneMore: function(arg){
            return helperUpper(arg);
        },
        
        // unless it's super generic, then it goes at the bottom. 
        _count: function(f){
        
        }
        
    });
    
})(dojo);

could you, for example, arrange it so that properties are private but you have public setters/getters? Or once the closure fires the variable is accessible but cannot be updated?

not with es3 ... which is everywhere. modern browsers you could use defineGetter et al and accomplish this, but I'm a pragmatist and also still have to support ie6 in most things, so it's more of a pipe dream.