This is how you create a True Crypt volume on /dev/hda3.
Code:
truecrypt -c /dev/hda3
Answer the questions. Once all of the questions have been answered it will create the True Crypt volume on /dev/hda3.
This is how you map the True Crypt volume whether it has a file system or not.
Code:
truecrypt -N 3 /dev/hda3
It will prompt you for the password. When you enter the password it will map /dev/hda3 to a virtual device named /dev/mapper/truecrypt3.
Once the partition is mapped to a True Crypt virtual device you can format it.
Code:
mkfs -t ext3 /dev/mapper/truecrypt3
If the partition has already been formatted via a True Crypt virtual device then in the future you just map the partition and mount it.
Code:
truecrypt -N 3 /dev/hda3
Password:
mount /dev/mapper/truecrypt3 /home
The man page for True Crypt is helpful. I mainly used the examples at the end of the man page to figure out how to work with True Crypt.