You need to perform these steps only if you are using Solaris or Linux platforms.
Create a MySQL user account.
Refer to your operating system manual for instructions on how to create a user account. It is recommended that you create an operating system user account called mysql and group called dba for performing MySQL operations. Ensure that install-dir/mysql and its subdirectories including the data directory are owned by this user account.
Initialize the grant tables.
On Solaris, at the command prompt, you can use the following commands to initialize grant tables:
See http://dev.mysql.com/doc/refman/5.0/en/index.html for detailed post-installation instructions for setting up MySQL.