Which one is your favorite installation method?
FTP, HTTP, NFS (network installation)
HDD or directly threw cd/dvd?

I found that:
HTTP installtion does not support Graphical Installation.
NFS is the fastest and easy installtion Supports graphical installation).

why partitions are necessary?
There are many. Like to limit the users from filling all the hard disk
with data.
Practical thing I experienced was a DOS (Dinal of service attack) on
my test server causing all the space filled with log files.
there are many good points and everyone must make partitions.

main partitions are :
/ is your mount point
/boot (100Mb is enough as this partiton holds grub bootloader)

/var ( for the server files like web pages, ftp so it's size depends
on how much you going to put for web)
I share a lot of mp3s on my server @ home so my partition is around
2000MB.

/usr (Contains most of the applications and utilities thus it's
decision depends on how much applications you want.)
I use many applications also i try new things so I found 3 GB is enough.

/tmp (name is obvious this partition holds the temporary files best
practice is to put iton a different hard disk as this thing ensures
proper working of those applications which require to write in to /tmp.

/swap (it should be double of the your ram size, processor uses this
partiton as an extra ram )

/home (again this partition depends on how many documents , files
e.g. mp3, pictures etc). I download a lot so I gave it 1.5 Gb.


If you want to add more/feel corrections installations feel free to
share.
Plese be careful when you insall. It is just a brief information and
not the full installtion cross check everything before installation,
read shipped documentation with your distro n undestand before acting
regds
anuj