BSD 4.10 install question

[Harry Heim]

Hi,
I am about to install BSD 4.10 and according to "The Complete FreeBSD" 
4th ed, (Lehey) all I need is on the installation CD, (the first disk).  
He  says little about the second CD, "Live File System" and what needs 
to be done about it.  Any good advice as to just what and how the second 
CD is used for?  Also, I am doing the install on 4GB HD and someone said 
use 256MB for root, 512MB swap, 256MB for /var and /tmp and the rest of 
the space for /usr?   This  is almost the install default as Lehey  says 
use far more for the root  so as not to run out of space.

Thanks
Harry