Utility or software to visualize Neural Network? I am using Octave to generate a Neural Network with a single hidden layer, and saving it as two CSV files. 

Is there a utility or software that will load the files and create an image, PDF or HTML page that displays the weights over edges connecting neurons?
If you have CSV files a quick way to generate images would be to open it in Excel (or a similar spreadsheet software) and use some sort of colour scale conditional formatting (under home>styles in Microsoft Excel) - set the width and heights of the cells to small in order to view all the data at once.

You could also use a surface chart in order to visualise the data in Excel.

Otherwise if you are familiar with a tool like Matlab or R, you might wish to use some sort of graphic tool to represent it, e.g. meshgrid in Matlab might work.  

Matlab and/or R can be programmed to load several CSV files and create graphics from them.  The first two techniques I mentioned (although accessible to a more novice computer user) have to be carried out manually.