So have you gone through the README in the MySQL install directory?
I.e.
1. Create group "mysql" (groupadd mysql)
2. Create user "mysql" and add to mysql group (useradd -g mysql mysql -d /dev/null)
3. Run (from source base dir) ./scripts/mysql_install_db
4. chown -R root .
5. chown -R mysql data
6. chgrp -R mysql .
7. ./bin/mysqld_safe --user=mysql &
I used this today and it worked perfectly