First, you need to know TCP/IP in details.
Any books, RFC on the subject is good.
Then, you need to know the mechanism of HTTP and other protocols like DNS and FTP.
Once you know this, you can read the CSS and/or CSM configuration material that you will find on this website.
The important things to remember from these manuals are the concepts and not the commands.
Like - what is a sticky connection ? On what parameter can you do stickyness ?
What type of loadbalancing are available ?
What's the difference between them ?
What's the advantage of one compare to another ?
By reading the configuration manual, you will see all these concepts. Try to understand them and ask yourself why we do it like this and not another way (if you know very well the protocols involved like TCP and HTTP, you should know why).
I hope this will help.
Gilles.