there is a fairly neat perl script called mysqltuner.pl (available at the domain of the same name, or here)
you need shell access (and a mysql admin user login) - but it will look at your instance, config and some stats and make basic recommendations that could provide a base from which to work.
while it's a good starting point, it certainly isn't an absolute diagnostic tool & band-aid - I would still have a go with the numerous web resources dealing with MySQL performance tuning, and preferably start (on a development box) understanding how to measure your current performance, understand indexes and how they are applied and how different mysql datafile/db storage types work and what suits your environment.
as someone once muttered in Oracle training, there is no "faster=true" switch.