With Venture, you can add testimonials easily by going to Testimonials → Add New in your dashboard. Testimonials are composed of the testimonial text, the name of the person, and an image (which can be added as a Featured Image).
All testimonials are displayed in an automatically generated testimonial archive page. The testimonial archive page can be found on your site at http://mygroovysite.wordpress.com/testimonial/ (replace http://mygroovysite.wordpress.com/ with your own site URL).
You can add the testimonial archive to a Custom Menu, using a custom link