How to backup and migrate Drupal

Download and enable Admin Menu
 
Download and enable Backup & Migrate
 
Backup /htdocs/sites
 
Backup database with Backup & Migrate module
 
Put site into offline mode
 
Change theme to Garland
 
Disable contrib modules
 
remove Drupal files from /htdocs
 
Download and extract new Drupal files to /htdocs
 
Copy orginal /htdocs/sites directory into new Drupal files.
 
Change system user permissions for contrib modules directory.
 
Run http://drupaladmin.net/update.php
 
Change to normal theme
 
Run http://drupaladmin.net/update.php
 
Enable contrib modules.
 
Run http://drupaladmin.net/update.php
 
Verify content is there, featuers are working, and your status report.
 
Backup everything once it is up to date.