hi everyone,
i wanted to build a linux system from scratch and than i came to know about the LFS.
people i aware with the following concepts:
C
C++
Core Java
Operating system concepts such as:
memory management
kernel
scheduling
multitasking etc.

I would like to know where to start with? how to start? which books shall i refer?
And one more question..I know it shouldn't be questioned but i wanted to know on an average how much time it would take to complete as i have limited free time to work on this project. so just wanted to have an idea to prepare a schedule.
I would be grateful for any replies.

Start by reading the LFS or CLFS book that you plan to use. You can build a base system in a weekend on a reasonably new machine. Could take a week or more on an older machine.