The Guide shows you How to Format the Partitions on Disk by Linux Command Line Tools.
All Steps are Clearly Delineated Reducing at Minimum the Eventuals Choices and Customizations to Make Clearer & Easier the Process.
So if you Have Some Doubt or Need Some More Insight you Should Consult the Official Online Documentation…
Just Relax & Take the Time of Carefully Reading and Executing the Instructions Contained Here and All should Work Like a Summer Breeze :)

For the Sake of Clarity I Take Into Account Only the General Case of Formatting Two Partitions on Disk:
One Swap Partition
One Root Partition
Here is the Detailed Guide for Partitioning with fdisk:
fdisk Partitioning Getting-StartedTo Enable/Format the Swap Partition:
We Suppose that’s the First, One.
mkswap /dev/sda1
swapon /dev/sda1
Formatting the Root Partition:
We Suppose that’s the Second One.
mkfs.ext3 /dev/sda2
Here I Choosen the ext3 Formatting but we Dispose of Many Other Choices See:
mkfs -h
.