Manuals can be found underneath each plugin on your plugins page in-account, just under the download buttons.
Click the View button to the right of the User manual text to open the manual in a new window:
If you can see the plugin name, but not the download or view buttons, expand the listing by clicking the (+) button to the right of the plugin name.
Manuals for older products (like Revoice Pro 4 or VocALign Project 3) can be found in the right-most column on our legacy downloads page instead.