i need to interface usb barcode reader wit a controller and display the code in lcd. i dunno how to chose correct controller with usb module. help me to choose a right module....
Ummm is that related to arduino it looks like u are not trying to do something related to arduino but if u ...............
get youe self a ardunio and a usb host sheild from spark fun ! then a lcd then work out month on how to interface that barcode scanner to the arduino 
( it will involve a hell lot of programming 
or scrap the idea 
and get something that can do what you want !
Search for an old barcode scanner with serial port or see if you can bypass the usb part (open the scanner and see if it has a serial to usb converter)
An arduino as a usb host is to complicated (cost to much memory/ processor power)
Most of the USB and serial barcode scanners that I have seen just emulate a keyboard. Has anyone ever gotten a keyboard to work with an arduino?
Yes. It is well documented.