Web-based Application using MySQL as database

Im developing a web-based application in which my site has three kind of users; Guest, Registered User and Admin. Guest can only access certain contents of the site while both registered users and admin have full access.

As im quite new to MySQL, so im a bit lost (Tho I can use 3rd party program to manipulate the database on the fly). In MySQL, there is a database called, consisting many tables. One of them is which stores infomation who can access that particular database.

My question is:
1) Does every registered User information such as password and user ID must be stored in the table of database or enough to use one ID and password for this group (Since MySQL does support Multi-User connection)

2) What is the best way to store images, video, and Audios? Store as binary object or store the path to the files (its location)?? I ve been reading both pros and cons of the two approaches and now still skeptic which one to choose.

Any suggestion/advice are most welcomed and I truely appreciate it. Thanks in advancw