I've built a check list for each time I upgrade Drupal, whether it's a simple (incremental) version upgrade (version 5.4 to 5.7) or a full version upgrade (from version 5 to version 6).
- Copy the drupal and module files to the web server.
- Unzip (using tar) the main drupal file.
- Unzip the modules.
- Configure the sites directory for each website.
- Log into the website with the Administrative account (Account #1)
- Disable all modules (/admin/build/modules)
- Put database in maintenance mode
- Backup database to flat file.
- Update apache configuration to point to new version (commenting out the old lines - by commenting them out, you can easily uncomment them if you have to do a recovery and comment out the newer version).
- Connect to the website url, adding update.php to the end (to start the update process).
- Follow on-screen prompts.
- Enable all modules
- If you're using WyzWig module, Go back and enable module "Tiny mce" (enabling WyzWig disables it for some reason)
- If you're using the node_permissions module, Run node_permissions module.
- Re-run update.php
- Configure the WyzWig Editor module (this seems to lose it's configuration with some upgrades, for some reason), and any other modules you need.
- If you've added or upgrade any modules, fix the role permissions (/admin/user/permissions)
- Take database out of maintenance mode.
- Verify as an anonymous user (by logging out) that the site looks the way you want and that the functionality works correctly.
- Drop all tables in the database.
- Reload the backup into the correct database.
- Update apache to point to the correct directory (uncomment the old lines and comment the new lines).