@vignesh, please post your threads in proper sections. Then only this thread can attract appropriate people.
As for your question, you might want to have a look at this documentation that some of my students did for remastering and creating a custom GNULinux distribution.
*db.ilug-bom.org.in/lug-authors/anurag/gnoware-final-documentation-1504.pdf
Also check the Gnoware documentation available from HBCSE's site:
*www.gnoware.org/ebooks.html
You might also want to have a look at these and see if this helps your purpose:
1) From Power Up To Bash Prompt
*tldp.org/HOWTO/From-PowerUp-To-Bash-Prompt-HOWTO.html
2) Pocket Linux guide.
*pocket-linux.sourceforge.net/
I have more such documentation , but you should be ready to read a lot.