Below is reference of how I have setup chroot SSH jail for users in CentOS-4.6 with ISPConfig installed replacing the openssh rpm with the one from chrootssh.sourceforge.net .
It's easy on ISPConfig as support for chroot SSH is now built in with the control panel, you simply need to get chrootSSH installed and then enable the ssh option located in the config file at "/home/admispconfig/ispconfig/lib/config.inc.php":
$go_info["server"]["ssh_chroot"] = 1;
If you need for the ssh chroot to access additional application, the file "/root/ispconfig/scripts/shell/create_chroot_env.sh" which builds the chroot needs to be edited. Also, check and edit the location of mysql socket file.