There are a number of Differant GUI Tools for MySQL.
Probably the most common is phpMyAdmin which is usually offered through your hosting provider,, it is a web based MySQL GUI Tool.
MySQL Workbench is another GUI Tool created by the people that created MySQL:
On my Mac I Use Sequel Pro:
On my Windows system I use Heidi SQL:
Navicat is another popular GUI Tool and is available for both Win and Mac OS: