Programming your .mobi Web site doesn't have to be difficult. The mobile Web is governed by Wireless Application Protocol (WAP) 2.0, which uses Extensible Hypertext Markup Language-Mobile Profile (XHTML-MP) as the programming language.
XHTML-MP is a variation on XHTML, so if you know one, you can quickly learn the other. In addition, wireless CSS can be used for mobile Web sites in the same way it’s used on regular Web sites.
For more information on programming, download the "DotMobi Mobile Web Developer Guide" from the mTLD Web site.