how many CDs for v3.1 r3?

["anonymous" <call_ret@yahoo.com>]

I was planning to download and test install Debian for the first time.
However, when I browsed the website below:

http://cdimage.debian.org/debian-cd/3.1_r3/i386/iso-cd/

for a download, I found out that I would need to download 18 CDs: 15
regular and 3 for the update.

I would like to know whether all these CDs have binary files or are
these also include CDs with
sources and documentation. If so, which ones of them?

How much would it need for a complete install on a P-IV 2.5GHz with 256
MB RAM?
And how much for the disk space?

I tried to look up the answers in the online manual, but was unable to
find them. Any help would
be appreciated.

Thanks in advance,

A.