If you're running an older version of DbVisualizer, you find the corresponding Users Guides in HTML (online) and PDF (download) formats here:

DbVisualizer 9.5HTML PDF
DbVisualizer 9.2HTML PDF
DbVisualizer 9.1HTML PDF
DbVisualizer 9.0HTML 
DbVisualizer 8.0HTML PDF
DbVisualizer 7.1HTML PDF
DbVisualizer 7.0HTML PDF
DbVisualizer 6.5HTML PDF
DbVisualizer 6.0HTML PDF
DbVisualizer 5.1HTML PDF
DbVisualizer 4.3HTML PDF
DbVisualizer 4.2HTML PDF
DbVisualizer 4.0HTML