Hi mohan_nalla,
You will find lot of material - tutorials, howtos, ebooks, programming examples, ports, etc for both uC/OS and Linux in the internet. You just need to have patience to search and sort them out.
learning for ucos : labrosse book and micrium site
linux : first install linux(good to stsrt will be ubuntu),tldp site docs , any book like running linux or linux for dummies(go fast thru them)