Bash Script md5sum checking dirs

I need a script that will check my website files and folders and alert me by email if any files change or are added to the system. Is a basic security script that should use MD5 to check files for any changes, and most importantly if files are added to the directorys within my webserver. I would like to run it via cron every hour. It should email me with the alert, and also what file has been added or modified. I am using centos Thank you