How to design GUI for my embedded design
This depend on which operating system you are using.

If you are on linux, i would recommend you using gtk/glade.


Install GCC and other basic requirement,then install GTK library
Install Glade in your system which is used to make UI interface
Choose you IDE, like eclipse is best in this case. Add path to your gtk libraries in eclipse 
Make UI in glade and then program it using gtk libraries in eclipse.


This is all you require to build a professional level GUI in linux for your embedded design.

If you are in windows , I would say go for visual studio . It is best and provides many functionality.