Hello! Untill now I am using 8,16 bit processor & programming using assembly language. Now I am switching to embedded C & ARM core processor like LPC1768 & STM 32. So can i found some primer for this processor anywhere?
The ARM technical manuals are generally very good. For the Cortex-Mx parts see the books by Joseph Yiu.
Where have you looked? Try going to the home page of this website (click on the house icon above) and click on "Books" listed under "Other Information"
Maybe the Getting Started Book helps you that is available under http://www.keil.com/mdk5.
Watch the trailing point at the end of the link.
This will work better:
http://www.keil.com/mdk5