Databases and mySQL what?

It appears that freewebs already offers this capability - see Ratings/Comments feature at Freewebs.com. Even if you have to pay for it, it will be far cheaper than trying to come up with something yourself.

Your options for doing it yourself are going to be very limited or nonexistent since a) you don't have control of the web server itself, nor b) your own database server, and c) you want it all for free. One crucial aspect of adding the features you desire is security. If you do it wrong, the web/database server gets comprised. This entails more than just getting the functionality working.

Yes, but not without having access to the web server, or pre-canned functionality and/or cgi/asp/php support from the hosting provider. Something has to process the information when the button is clicked, typically a script on the web server, so the hosting provider has to offer script support. First, Google for "free asp hosting" or whatever language (asp, cgi, php...) you want to learn and choose a host. Then get a good book on the language and security, learn it, and then look for free scripts or write your own. Microsoft also offers extensive training info at The Official Microsoft ASP.NET Site and php tutorials are only a Google away.