phpMyAdmin is a tool, written in PHP, that allows you to handle the administration of a MySQL database server. You could always download the MySQL GUI tools, but the problem there is that you need to give external access to a user account, which isn't always possible to do. This is where phpMyAdmin steps in.
The tool is easy to use and I have done some tricky stuff with it in the past. It can do everything that you need it to do with MySQL.
I have tried to install phpMyAdmin a couple of times and have failed each time. Admittedly, I only attempted it half-heartedly, but this is the only stumbling block I can see in the average user trying to use this system. However, many hosts will give you access to this tool as part of the hosting package, and it is only really needed if you expect to do a lot of database administration otherwise you can just run PHP scripts.
The website contains extensive documentation, and even if this isn't enough there are a few books available for the tool.