If your running linux you probably already have openssh running.
try this ...
Code:
$ /etc/init.d/sshd status
sshd (pid 3904) is running...
For sftp-server (sftp) to work you need this line
Code:
# override default of no subsystems
Subsystem sftp /usr/libexec/openssh/sftp-server
to be in your /etc/ssh/sshd_config file.
Remember that FTP is not like SFTP at all. sftp just uses the users' home dirs. If you want your system to be secure I recommend getting a oriely book and checking out the openssh.org home page.