Exporting
yWriter includes a wide range of export routines (Text, RTF, HTML and others.)
Version 5.1.6.2 and later include several new features which make life easier when creating ebooks. For example, if you put a @ in front of your chapter title, the title will be hidden in the exported file. (Useful for copyright pages, blurbs, etc) However, the chapter will still begin on a new page.
Recent versions of yWriter (5.1.9.7 and above) include the option to always export a scene, or only export a scene when the destination is one of html, rtf, rtf individual chapters, or latex. This allows you to create scenes which will only appear in your ebooks, for example, and others which will only appear in Latex export for print editions. This is a very powerful feature, because it means you can have one project which will create rtf, ebook and print editions of the same work, all with different front-matter and content.
Exporting to HTML
There's also a new 'Export to Ebook' entry under the project menu. This will create an HTML file specially formatted for really easy conversion to ePub, Mobi and other ebook formats using Calibre.
If you type the word <html> as the first line in a scene, the scene will be included as-is in all html exports. This means you can include html code for images, special formatting, hyperlinks and so on. (Usually scenes are converted from RTF and reformatted, which means raw html code won't work.)
You can also include html code within your scenes by using <htm and /htm> tags. Note the space before the / in the closing tag.
Exporting to LaTeX (and PDF)
Version 5.1.7.0 and above include a new 'Export to LaTeX' feature. (What is LaTeX?) You can pick or create your own template (e.g. 5x8" book) and export a fully-formatted document in TEX format, which can then be converted to PDF using TeXnicCenter (part of the proTeXt TeX distribution, which is also freeware.)
As above, if you type the word <TEX> as the first word in a scene, the rest of the scene will be exported to LaTeX format as-is, without any conversion.
You can also enclose LaTeX commands in your text by enclosing the commands with <TEX and /TEX> (There's a space before the / in the closing tag.) This allows you to include special characters, images ... any code you like.