Something I have to do very often when I install TYPO3 is to convert the MySQL database where TYPO3 will be installed to the UTF-8 charset.
It's really simple to do on an empty database and the MySQL command used to do it is as follows:
ALTER DATABASE DBNAME CHARACTER SET utf8 COLLATE utf8_general_ci;
Just replace DBNAME above with the name of your databse and that should work. Also, you can use any character set you'd like, but this example shows what to do for UTF8.
Remember, this only works on the database itself and not on any of the tables in the database, so if you need to adjust the character set of existing tables, you'll need a different command to do it. The command needed to do that can be found where I found the above command at A2Hosting's helpful site.