What tools helps designing sites which would be mobile phone friendly ? Something that would product the right CSS, the right html, etc
I doubt you'll find too much that would make good markup for mobile phones across the board.
Here is a table for compatibility for different mobile browsers: http://www.quirksmode.org/m/table.html
If you are trying to make a page that works in a ton of mobile browsers, keep that chart close by.
If you are just looking for a way to make iphone specific mobile sites, you should check out jqTouch and/or XUI JS
The mobile aspect really has to be considered at the outset. Good, well-planned, structured site with textual content designed to be compatible to be appropriate for reformatting, and tailor-made css for media=handheld is your best bet.
If you want to try something very mobile specific, what about WALL http://wurfl.sourceforge.net/java/wall.php?
There are no tools that would magically produce the “right” HTML or CSS. When writing HTML and CSS for Mobile Safari you simply stick to standards, for example HTML4/5 and CSS2+. The hard part is the design, and I am afraid there is no automatic solution. You have to design around the platform’s shortcomings (no mouse cursor, for example) and play to its strengths. A good document about writing web sites and applications for Mobile Safari is the Safari Web Content Guide by Apple.
You could use the Dashcode IDE which comes as part of the Apple Developer Tools. It comes with a collection of templates for creating web content to target the iPhone.