1.Deactivate and delete any other caching plugin you may be using. Make sure wp-content/ (temporarily) has 777 permissions before proceeding, e.g.: # chmod 777 /var/www/vhosts/domain.com/httpdocs/wp-content/ using your web hosting control panel or your SSH account.
2.Login as an administrator to your WordPress Admin account. Using the "Add New" menu option under the "Plugins" section of the navigation, you can either search for: w3 total cache or if you've downloaded the plugin already, click the "Upload" link, find the .zip file you download and then click "Install Now". Or you can unzip and FTP upload the plugin to your plugins directory (wp-content/plugins/). In either case, when done wp-content/plugins/w3-total-cache/ should exist.
3.Locate and activate the plugin on the "Plugins" page. Page caching will automatically be running in basic mode. Set the permissions of wp-content back to 755, e.g.: # chmod 755 /var/www/vhosts/domain.com/httpdocs/wp-content/.
4.Now click the "Settings" link to proceed to the "General Settings" tab and select your caching methods for page, database and minify. In most cases, "disk enhanced" mode for page cache, "disk" mode for minify and "disk" mode for database caching are "good" settings.
5.Optional: If you already have a content delivery network (CDN) provider, proceed to the "CDN Settings" tab and populate the fields and set your preferences. If you do not use the Media Library, you will need to import your images etc into the default locations. Use the Media Library Import Tool on the CDN Setting tab to perform this task. If you do not have a CDN provider, you can still improve your site's performance using the "Self-hosted" method. On your own server, create a subdomain and matching DNS Zone record; e.g. static.domain.com and configure FTP options on the CDN tab accordingly. Be sure to FTP upload the appropriate files, using the available upload buttons.
6.Optional: On the "Minify Settings" tab all of the recommended settings are preset. View your site's HTML source and search for .css and .js files and then specify any CSS and JS files in the respective section. In the case of JS files you can (optionally) specify the type and location of the embedding using the drop down menu. See the plugin's FAQ for more information on usage.
7.Optional: On the "Database Cache Settings" tab the recommended settings are preset. If you're using a shared hosting account use the "disk" method with caution; in either of these cases the response time of the disk may not be fast enough, so this option is disabled by default.