Here are some tips on designing website for mobiles and tablets:
- Choose a separate URL for your mobile site
- Choose column page structure. Most important information should be on the top of the page like site search and navigation.
- Reduce your navigation and user Input.
- Do not use flash, java, frames and pop-ups. Minimize the use of images.
- Have more than one mobile website for differnent devices like ipads, iphone. his will enhance the experience of the user.
- Use the phones built-in functionality like “Calling” a particular phone number just by clicking it.
- Testing the website for mobile devices. you can use Enter Opera Mobile Emulator. The Emulator supports around 20 different platforms.
- Give users the option on viewing FULL SITE option
- Your site must use CSS for the layout to ensure maximum compatibility. Avoid using tables.
- Design the website for for fingers. Click targets should be a minimum of 30-40px in size and use whitespace in between elements to ease clickability.
- Filling forms can be difficult on mobile device so offer radio buttons and lists wherever possible. Also, reduce the number of screens a user passes through to complete a form. Form labels should be top aligned rather than left aligned to save space.
Here are some awesome examples:
Hope this helps you to built a user-friendly mobile webiste.
Take Care 
