To install MySQL use your Linux's package system or install it manually by downloading it from http://www.mysql.com/downloads/mysql/ and following their instructions.
With MySQL installed and started create a MySQL database named eHour by executing the following command and replacing user with a database <user> that has enough priviliges to create a new database:
mysqladmin create ehour -u <user> -p
Install eHour database
With the ehour database created the next step is to create and initialize the datamodel.
sql/mysql/install directory there's a
fresh.mysql.sql script which contains the datamodel and default data.
Execute it by running the following command - replacing <user> with your database user:
mysql ehour -u <user> -p < fresh.mysql.sql
The standalone distribution does not contain the fresh.mysql.sql, it's available at this location.