Prerequisites for Mobile User Interface?

It’s my first time that I need to design a user interface for mobile devices. So I’m wondering what are the prerequisites that I need to know before I start crafting the design.

All I have as start-up information is a fixed 320x480px resolution.

Any more details I need to know?

Try not to think about resolution. Some mobiles are even smaller than that - and remember that it is the low end mobile phones that you need to design for, because the higher end smartphones will probably be able to use your normal website without too much difficulty.

In terms of layout, try to linearise it so that it just flows from top to bottom, with no kind of float or positioning of any sort. In terms of technical construction, try to avoid using scripts as far as possible, and remember that many CSS features will not be fully realised on all devices.

Think about the different restrictions on interaction. The most you can realistically expect is that people can scroll through the page, and select and action hyperlinks and buttons. Anything more than that and you are likely to exclude some users.

You really need to keep the page lean. Use the minimal markup you can. Shrink and optimise any images so that users aren’t downloading more than they need to over what could be a slow connection.

Keep it simple.

Yeah, researching trough various articles at I realize more-or-less the same thing. Thanks!