Probably half the questions in this forum involve where to find something. A few simple tools will allow you to answer most of your own questions.
1. Firefox + Firebug extension. Turn OFF all caching in your Dolphin admin section, else Firebug will be useless. There are plenty of video tutorials on YouTube on how to use Firebug. Firebug will help you find where to change a page elements CSS, and also help you locate specific html code. Particularly useful html code to search for, will be html element ids or class names. If you need to find which one of Dolphin's 5000 files contains a specific piece of html code, it's not that difficult, but it begins with Firebug. Firebug will tell you directly, which css file contains the css rule for a page element. Firebug will also show you the html code that makes up the various page elements, but it won't tell you in which one of Dolphin's files to find it. Firebug just tells you what to look for.
2. Keep an unzipped copy of Dolphin on your computer for the purpose of finding things.
3. Download and install Agent Ransack. Agent Ransack is an excellent free file search utility, that you can use to search Dolphin's source files for the html code that Firebug found for you. For instance, if you want to find the file that contains the code that makes up the profile thumbnail at the top of any page, Firebug will find this code for you: <img class="thumbnail_image_file bx-def-shadow bx-def-round-corners"
Right click on the folder that contains the Dolphin source files on your computer, then select Agent Ransack. Agent Ransack will start and be pointed to this folder. Enter thumbnail_image_file bx-def-shadow bx-def-round-corners as the search term then start the search.
After a short time, Agent Ransack will tell you that this code exists in these two files:
/templates/base/thumbnail_single.html
/templates/base/thumbnail_couple.html
Then, you can just right click on the file name in Agent Ransack's search results, and select 'Edit with Notepad ++' to view or change the file. What? You don't have Notepad ++ ? Why not? It's free. Google it.
Oh.... here's the code in thumbnail_single.html
<div class="thumbnail_block __classes_add__" style="float:__sys_thb_float__;">
<div class="thumbnail_image" onmouseover="javascript:startUserInfoTimer( __iProfId__, $(this).find('.sys-online-offline:first') )" onmouseout="javascript:stopUserInfoTimer(__iProfId__)">
<a href="__usr_profile_url__" title="__usr_thumb_title0__">
<img src="<bx_image_url:spacer.gif />" style="background-image:url(__usr_thumb_url0__);" class="thumbnail_image_file bx-def-shadow bx-def-round-corners" />
<i class="sys-online-offline sys-icon __sys_status_icon__" title="__sys_status_title__"></i>
</a>
</div>
<bx_if:profileLink>
<div class="thumb_username">
<a class="bx-def-font-large" href="__usr_profile_url__">__user_title__</a>
<br />
<i class="bx-def-font-small bx-def-font-grayed">__user_info__</i>
</div>
</bx_if:profileLink>
<div class="clear_both"></div>
</div>
That code highlighted in red, is a Dolphin template key. You'll find them all over the place. This particular template key is replaced with the logged in user's profile thumbnail when the template is parsed.
Total time to find this code with the aforementioned tools: About two minutes. Time to find the same code by asking where to find it in these forums: Maybe a few minutes if you're lucky.... maybe a few days if you're not so lucky... maybe never