accessing data from a json file writing javascript or using jQuery

I am trying to create a page from json objects using javascript. I have this huge json file containing several objects that contain arrays for the objects. Also, I believe it writes some html for breadcrumbs or navigation bar. The entire page is built from this json file, but I can't figure out how to code the javascript or use jquery to get the page to display in the browser.

I've tried using alert() or document.writeln(), document.write() to at least see if I am correctly accessing the attributes in the json file. Nothing is working. I'm new to javascript using json to create html pages, objects and accessing objects in json writing javascript. Here is some code:

    var novdata= {
'categories':[
{N:'nwItem1',O:'Composition',V:School Supplies > Paper> Notebooks},
{N:'nwItem2,O:'Crayons',V:'Elementary > Art > Art Supplies'},
{N:'nwItem3',O:'Calculators',V:'High School > College Prep> Trigonometry'},
{N:'nwItem4',O:'Maps',V:'Middle School > US History > Civil War'}
],

'brands': [ 
{N:'nwItem11',O:'National'},
{N:'nwItem22,O:'Crayola'},
{N:'nwItem33',O:'Texas Instruments'},
{N:'nwItem44',O:'Atlas'}
],


'grades': [
{U:'http://www.donson.net/cp/Notebooks-Academic-School/RED-43481.',O:Kindergarten},
{U:'http://www.crayola.com/',O:'Fourth Grade'},
{U:'http://www.ti.com/',O:'Twelth Grade'},
{U:'http://shop.nationalgeographic.com/ngs/product/books/atlases-and-reference/national-geographic-9th-edition-atlas-of-the-world---softcover?code=SR60001',O:'Sixth Grade'}

],

'purchase': [
{U:'http://www.amazon.com',O:Kindergarten},
{U:'http://www.walmart.com/',O:'Fourth Grade'},
{U:'http://www.overstock.com/',O:'Twelth Grade'},
{U:'http://www.bn.com',O:'Sixth Grade'}

],

}

alert("I am testing " + novdata.categories);