Sharepoint 2013 Javascript Jquery actions

You are right, MANY things happen on page after $(document).ready(). 2013 does provide a few options.

1) Script on Demand: (load a js file then execute my code.)

function stuffThatRequiresSP_JS(){
//your code
}
SP.SOD.executeFunc("sp.js")

2) Delay until loaded (wait for a js file, then run)

function stuffToRunAfterSP_JS(){
//your code
}
ExecuteOrDelayUntilScriptLoaded(stuffToRunAfterSP_JS, "sp.js")
3) load after other stuff finishes

function runAfterEverythingElse(){
// your code
}
_spBodyOnLoadFunctionNames.push("runAfterEverythingElse");
Sources:

executeFunc: http://msdn.microsoft.com/en-us/library/ff409592(v=office.14).aspx

ExecuteOrDelayUntilScriptLoaded: http://msdn.microsoft.com/en-us/library/ff411788(v=office.14).aspx

Cant find a source on _spBodyOnLoadFunctionNames but I am using it in a few places.

good luck.