For this Tutorial you will have to have some basic knowledge of PHP and mySQL, hopefully you won't need much though.  It is also assumed that you have a good understanding of Flash 5 Actionscript.   What this tutorial basically does is to show you how to set up a table in a mySQL database, then using PHP (or asp with a few minor changes) manipulate that table and interact with Flash.  The first part of the Tutorial shows you how to create a unique user ID in the database, In this case it will be the persons name.  With a few minor changes however you'll be able to make it a secure password protected user login.  The unique user ID is required because in the next part we'll be saving the position of a couple movie clips and some of their property's.  In this way a user can return to the (your) site at anytime and the movie Clips will be in the exact same position that they left them in. I also added in a place for the user to add in a comment, which is also saved.  With a couple modifications you can turn that into a guest book or anything else you can think of.  For a working example of this tutorial please goto http://www.flash-db.com/Ex1/Ex1_SaveMovie.html. This is a much more of a hands on tutorial so it's helpful if you follow the scripts and Fla source included, in addition to viewing the working example at the same time. 

It is recommended that you read over the PHP scripts first. These have all been extensively commented.  In PHP the # symbol is a comment.  Also it may be best to try to follow the code in the included Flash movie along as well.