Does anyone know of any tutorials that involve developing a UI for a game under DX?

Hey, i made a post very similar to your own a month or so ago, there are a number of librarys you may be able to adapt to your project. Make sure you have a look at this thread:

http://www.gamedev.net/community/forums/topic.asp?topic_id=444948

In the end i looked at these examples and developed my own user interface specifically for my application, it wasnt very advanced but it did the job :). I simply retrived the cursor position, used nested if's in the display loop to indicate when a mouse over occured, or the mouse click case in the Windows Process function to define when a button had been clicked (and rendered a new image onto the button showing the mouse had been clicked, and maybe performed a certain function). Its not that hard really, but if you want when i get home i can PM you some examples of the type of code i used.