Hi Ricky, I'm don't know a lot about html, but you could create your own .html file from scratch using C#, and then write to it to add whatever you need. The C# side is as easy as creating a file and writing to it. Check FileStream on MSDN for example. What you write you can learn about in the infinite html tutorials the web has to offer, but it will be just text, as it would be with a .txt file.

I used to have a template file with all the headers and footers and a few C# functions to add fields like paragraphs, pages, buttons, fonts, etc. You know what the report will be like, so you know what data you will be expecting and how to format it. Just add the fields starting and ending tags; for example <p> </p> and write text inside it.
Perhaps there is a specific html class in C# to do that even easier? I'm sure there must be a more 'professional' way of doing this.

As far as format goes, I'd go with browser based languages, as it will be easier to read on any computer.