password protected pages with cookies

Hi, I have a very general question about my php project. Basically, it's about secure pages for administering site. The way I do it is authorizing users against their credentials in the mysql database. Then if authentication passed successfully, I register a session with a specific name and do header() to move him to another page where he can edit content. Every move he/she makes in admin site it checks if specific session is registered, if yes it lets you do it and if not, sure it doesn't. Is this the simplest and relatively secure way? Or are there any other techniques for this? Thanks, Vlad