Linux MySQL Noob

Hello, I've got a Linux server running MySQL server.  It is up and running great, currently being used by one web app on this server and I don't want to break it.

What I would like to do, is create a new SQL database and a new username and password that a new web application (that I'm going to install on this server) can use to access the new database.

Can you tell me the commands that I need (there is no GUI on this server) to add a SQL database and a set of credentials to access the database with.  AND/OR a good web site or two that I can read to learn more about SQL.

To let you know more about the SQL that I'm running, here are the results of a 'yum list | grep -i sql'

mysql.i386                               5.0.22-2.2.el5_1.1     installed
mysql-server.i386                        5.0.22-2.2.el5_1.1     installed
perl-DBD-MySQL.i386                      3.0007-1.fc6           installed
php-mysql.i386                           5.2.2-3                installed
postgresql-libs.i386                     8.1.11-1.el5_1.1       installed
python-sqlite.i386                       1.1.7-1.2.1            installed
sqlite.i386                              3.3.6-2                installed


Thanks!!!