Documentation that led me to this fix:

1) https://github.com/visionmedia/express/wiki/Migrating-from-2.x-to-3.x
"the concept of a "layout" (template engine specific now)"

2) http://www.devthought.com/code/use-jade-blocks-not-layouts/

Updated package.json versions for express and jade from 3.1.0, >= 0.0.1 to 3.2.4, 0.30.0 respectively.
Added extends layout and block content to about.jade and home.jade.
Referenced the block content from specific jade files in layout.jade as "div.container!= body" seemed to be generating the following error when requesting home:

ReferenceError: home.jade:23

body is not defined
    at eval (eval at <anonymous> (MySite/node_modules/jade/lib/jade.js:171:8), <anonymous>:238:64)
    at MySite/node_modules/jade/lib/jade.js:172:35
    at Object.exports.render (MySite/node_modules/jade/lib/jade.js:206:14)
    at View.exports.renderFile [as engine] (MySite/node_modules/jade/lib/jade.js:233:13)
    at View.render (MySite/node_modules/express/lib/view.js:75:8)
    at Function.app.render (MySite/node_modules/express/lib/application.js:506:10)
    at ServerResponse.res.render (MySite/node_modules/express/lib/response.js:756:7)
    at exports.home (MySite/routes/index.js:19:7)
    at callbacks (MySite/node_modules/express/lib/router/index.js:161:37)
    at param (MySite/node_modules/express/lib/router/index.js:135:11)
GET /home 500 22ms