Amongst the hypertext, you will almost always find gold.
You will spend a lot of time reading the source code of a page when playing EBONY. Simply put, this is the "code" that controls the colours, images, text etc. that you see on the page. However, for those who are unfamiliar with this, it can be difficult to see what is "just code" and what is actually a hint for the level. The easiest way to show what is and isn't relevant is to become familiar with what the code for a typical EBONY level looks like:
<!DOCTYPE html><html><head><title>Some Appropriate Level Title</title><meta name="robots" content="noindex, nofollow"><audio autoplay loop> <source src="../common/trac01.mp3" type="audio/mpeg"></audio><link rel="stylesheet" type="text/css" href="../common/base.css" /><meta name="viewport" content="width=device-width, initial-scale=1"><script src="/common/imageMapResizer.min.js"></script></head><!-- A comment, which can only be seen here and not on the page itself --> <body> <div class="center"><img src="image-name.jpg" usemap="#part-of-an-image" alt="" /><map name="part-of-an-image"><area shape="circle" coords="430,44,20" title="Text Displayed When You Hover Over This Part Of Image" href="link-to-some-level.html"> </map> </div> <div class="hint"> <p><em>A line of text, in Italics</em></p> <p><strong>A line of text, in Bold</strong></p> <p> </p> </div> <script src="/common/mapFix.min.js"></script></body></html>
The parts with added emphasis are the most common places to find hints.
<title>...</title> - The contents between these two tags is displayed on the tab of your browser. In this case, it is "Some Appropriate Level Title". In an actual level, it is a hint for the solution.
<!-- ... --> - This is a comment; it can only be seen in the source code and not on the page. It usually contains a clue, and sometimes points to other clues on the page.
<img src="..." - The image source (or img src) is the file name for the image being displayed. Here it is "image-name.jpg", but usually it would be a helpful clue.
usemap="#..." - A map is a set of coordinates, which indicates a specific part of an image. This line of code simply tells the image to use the map, which will be defined on the next line.
<map name="..."> - The beginning of the map definition; the name of the map
<...title="..." - The text displayed if you hover over this specific part of the image
<...href="..." - The link to another page; the page you go to if you click this part of the image
Looking at these parts of the source code are a good start, and will provide you with enough clues to solve many of the lower levels.
On some levels, you may also need to look at other parts of the source code for clues. This is when it is particularly useful to have a familiarity with the way levels usually appear. If a part of the page usually says something like "trac01", "trac15", or "trac03" - then you can deduce that "track31" is intentionally different from the rest. Perhaps removing the "k" will take you to a different track, or the "k" is one of the letters in the solution.