We are going to redevelop one website we developed as an ASP.NET website to be a mobile one. So, I'm wondering how does the development of a mobile website differ from a normal one?
Also, what is the best approach to do this taken in consideration that this mobile website will be browsed mainly from iPhone?
I'm afraid you cannot use current asp-View to mobile especially for iPhone. There's special control set for iphone development - componentone.
If you web application is based on MVC or MVP patterns then moving will be not difficult.
There are a number of differences between a mobile device and a standard computer.
Users on smartphones are used a different experience.
In addition to Brian's answer I'd add:
I suggest that for developing a mobile website is to use the target smartphone for a few weeks to understand how the device is used in the real world.
Recently we have developed a site for iphone users, we are using asp.net/sql for normal site. But when you look at mobile sites, mobile normally have small screens and some time optimization problem.
We use jqtouch for mobile development. A JQuery plugin for mobile web development on the iPhone,Android, iPod Touch, and other forward-thinking devices.
Learning Video
Getting started
Establish the context for the mobile site: is there subset of information that is more relevant to your mobile users? Maybe your regular site has apps that are irrelevant on mobile devices? Either way, you should create your mobile site separately in a mobile folder! You can then use a sub-domain to reach it: for example, http://m.mysite.com
You can use a combination of CSS Media Queries and 51degrees.Mobi to detect browser features and render the correct size layout depending on which type of device the user has.
http://html5boilerplate.com/
http://www.modernizr.com/ (this is included in HTM5 Boilerplate)
http://51degrees.codeplex.com/
Do not make the stupid mistake of following current fads like "Responsive Web Design" which attempts to squeeze a desktop version of a website into a mobile screen. Above links should get you started.