Here's the output of the man page for ln, thought it might come in handy for all the people who come here for reference (The parent message is my second-most popular here!)

NAME
       ln - make links between files

SYNOPSIS
       ln [OPTION]... TARGET [LINK_NAME]
       ln [OPTION]... TARGET... DIRECTORY
       ln [OPTION]... --target-directory=DIRECTORY TARGET...

DESCRIPTION
       Create a link to the specified TARGET with optional LINK_NAME.  If LINK_NAME is omitted, a link with the same basename as the TARGET is created in the current directory. When  using  the  second  form with more than one TARGET, the last argument must be a directory;  create links in DIRECTORY to each TARGET.  Create hard links by  default,
symbolic links with --symbolic.  When creating hard links, each TARGET must exist.

Mandatory arguments to long options are mandatory for short options too.

--backup[=CONTROL]
make a backup of each existing destination file

-b     like --backup but does not accept an argument

-d, -F, --directory
hard link directories (super-user only)

-f, --force
remove existing destination files

-n, --no-dereference
treat destination that is a symlink to a directory as if it were a normal file

-i, --interactive
prompt whether to remove destinations

-s, --symbolic
make symbolic links instead of hard links

-S, --suffix=SUFFIX
override the usual backup suffix

--target-directory=DIRECTORY
specify the DIRECTORY in which to create the links

-v, --verbose
print name of each file before linking

--help display this help and exit

--version
output version information and exit

The backup suffix is `~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.  The version  control  method  may  be  selected  via the --backup option or through the VERSION_CONTROL environment variable.  Here are the values:

none, off
never make backups (even if --backup is given)

numbered, t
make numbered backups

existing, nil
numbered if numbered backups exist, simple otherwise

simple, never
always make simple backups

AUTHOR
Written by Mike Parker and David MacKenzie.

REPORTING BUGS
Report bugs to .

COPYRIGHT
Copyright ⌐ 2001 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO
       The  full documentation for ln is maintained as a Texinfo manual.  If the info and ln programs are properly installed at your site, the command

              info ln

should give you access to the complete manual.