Develop Reference

How to customize Nihilo.css?

One of the available themes in Dijit is Nihilo. I am using dijit/layout/.. for displaying some charts and graphs . I want to change some of the styles being used. Can any one tell me how to customize Nihilo.css and use the customized version?

Don't change nihilo.css, create another CSS file and put the link tag for the second file after the link tag for nihilo.css.
This way, if you upgrade Dojo, you will not have to merge your changes back in.

If you need to customize nihilo, I would suggest to have a look at this official guide Customizing a Theme.
Basically the idea is to build your theme, based on nihilo leaving the original nihilo untouched,.

TinyMCE integration - Plugins won't show

I apologize in advance if this is not the right forum for this question, but since I am in desperate need of help I hope you may want to help me out.
I am using TastyIgniter Online Ordering System for a project. The system has a description textbox where you can add information about the product. However, it is only a plain textbox without additional functionality like strong tags and it won't keep the formatting.
I downloaded tinymce, put the script files in the js folder, and added these lines of code into the PHP file:
<script src="http://localhost/assets/js/tinymce/tinymce.min.js"></script>
<script>tinymce.init({ selector:'textarea' });</script>
Hooray, it works partly. The textbox now has some of the functionality. It keeps the formatting and I am able to add bold, italic style to the text. Although, plugins like the image, table, hyperlink 'plugins' won't show at all. Is it possible that the textbox itself is restricted and then keeps the TinyMCE from showing these buttons or is something else wrong?
Thank you in advance.

You need to expand your TinyMCE init to include the plugins and toolbar/menu options you want displayed.
Take a look at this basic example of TinyMCE:
https://www.tinymce.com/docs/demo/full-featured/
If you look at the JS tab of the example you will see there are many options available for TinyMCE in the init.

When working with an already made website, how do you know which file to edit to change something?

Let's say I'm building a website and using an already made Wordpress theme. Say it's a pretty complex theme and there's a lot of folders and files. If I wanted to change something specific, like text, or an image, or something that happens in Javascript/jQuery, and the change that I want is not an option in the themes control panel, what do I do? I know I have to go into the files but how do I know which file to go to? Lately, I've just download the theme to my desktop and use the windows search companion and type in the field that says "a word or phrase in the file." Sometimes it comes up and sometimes it doesn't. For CSS changes I usually use Firebug and click on the element, but many times I want to change the HTML/PHP/Javascript. I feel like I'm doing it the wrong way and there's an easier way that I'm missing.

As you mentioned WordPress theme so I will specifically try to answer this question for editing WordPress theme.
When it comes to WordPress, everything is very structured and well organized. If theme written following standard practices then each component has its specific file. If you are familiar with WordPress theme structure and want to change php code or say a static part then all you need to do is locate the component file say sidebar.php, home.php, single-{type}.php, header.php and many similar files. http://codex.wordpress.org/Template_Hierarchy
Now if you want to edit something that is shown in right/left side of page as sidebar then chances of finding it in sidebar.php are maximum. Similarly to change something on home page try looking for home.php, for posts it could be single-post.php.
Many a times what you are looking to change might need a tweak in widgets. In this case, process remains same as theme you just need to look in different folder.
Javascript: For editing javascript, beautify the code if it came minified. When you have code ready much of js debugging can be done using firebug/Developer Console in chrome. Best way is to put breakpoints at relevant position and then inspect code behavior. You will be able to locate code block that you need to tweak to achieve what you want.
CSS: Create a child theme and then use it override default theme properties.

You can probably use grep in PowerShell, Cygwin, etc.
grep -lir "a word or phrase in the file." *
edit: Emulating Grep in Powershell

How to add javascript in addition to pure text in Joomla Article

More specifically I am trying to implement a wufoo form in a joomla article, but I need to add text, in addition to the code. I tried to just paste the code the article but all I get is the code as text. What am I missing? If it helps I have installed jCode, but I cannot find a way to add text as well in addition to the form.
I am open to other ways as well to solve this issue.

Joomla by default doesn't allow you to import code like PHP or Javascript through articles. For this, a plugin need to be used. I see you've tried using jCode, I've never used this before so can't provide any documentation on it.
I would strongly recommend using Sourcerer as a plugin for importing Javascript and PHP through your articles. It's free, well documented, well supported and easy to use. Once you've installed it, enable the plugin. Then in your article, you can use something like the following:
{source}
<script type="text/javascript">
alert('Hello world');
</script>
<?php
echo '<p>Hello world</p>!';
?>
{/source}
There will be a small button under the article textarea for Sourcerer which will bring up a popup window for you to enter all your code in.
Hope this helps

Alternate options are for your problem
If you are an admin user Remove filter option for article.
Go to article section -> Options -> Text Filter Options -> Choose your user group -> Apply no filter.
Another option is to create a module and assign that module to your article like below.
Create a module that have your forms. For module development tutorial
And create an article and set the module inside that like.
{loadposition contact_form_pos}
Inside your article just mention the module position like above
for more
Hope it make sense..

Add a code editor to a textarea via console/bookmarklet

I've run into an issue where I'm developing pages on a CMS which is out of my control, and I'm editing increasingly complex pages with nothing more than a textarea.
Initially I'm creating the pages in my code editor, then copying the HTML into the textarea. Keeping the local and CMS code in sync by hand.
This workflow sucks.
I'd like to have code highlighting, etc while I work within the CMS. Is there any way I can add a code editor like Ace or CodeMirror to the textarea via bookmarklet or console command? I've tried using the Ace Bookmarket Builder but I don't know if it's been designed to work on any page, or just github.
Edit:
I don't think I was clear enough above. I'm just an end user on this CMS, I have no ability to change how it functions on the backend. I literally just need a bookmarklet that finds the textarea and applies a code editor to it.

both tinymce and syntaxhighlighter are packages that are not tied to a CMS, so if yours is custom then you will want to try to use these together, I have heard of some success in this adventure in the Drupal (there is actually a project for it currently) arena but you may be looking at a bit of work to do so custom. there is chatter about this http://www.tinymce.com/forum/viewtopic.php?id=22901 <-here with even a plugin to tinymce :) hope this gets the ideas going!