A couple notes about HTML:

- Indentation of the first line of a paragraph will not translate to HTML, without getting into CSS formatting. Since Jinn is using software to make the conversion to HTML, rather than doing it by hand, I suspect the software doesn't generate CSS

- If you want something set off from the main body text - for example, the book excerpt that sugeneg mentioned - the block quote tag should be used:
Code:
<blockquote> Set off text </blockquote>
The blockquote tag will indent the text between the tags on both the left and the right.

When I submit a story, I send Jinn two files: a plain text version for him to convert to HTML, and a PDF version which retains all of my preferred formatting. I ask Jinn to leave my PDF file as-is, and he has always honored my request. The advantage of a PDF file is that it will retain the formatting on all computer platforms. Other formats may not. Of course, I can save PDF files natively from Mac OS X - if you're using Windows you may need third-party software.