error in mysql server

[Daniel Lacal]

I've installed mysql correctly (it worked) but now when I type 
> mysql

a message appears:ERROR 2002: Can't connect to local MySQL server (2)


and if I type 
> mysqladmin version

what appears is:

mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server (2)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock' exists!

I think that it don't works properly because  this file (mysql.sock) isn't here
'/var/lib/mysql'. this file is created in '/tmp'
What can I do?

                    Thank you
                
                    Daniel Lacal (d_lacal@stripped)