First of all: Websites made with VSD ARE html sites. The only difference is that you don't code the html, the programme does it for you.
VSD has interface for inserting description and keyword metatags, and also alternate text for images. You should use those in accordance with the Google recommendations. You can also insert Website analytics code for Google, Yahoo and Webtrends.
What VSD does not have is automatically inserting <h1> tags for the page header. But that can be done manually using the html tool.
Something to be aware of, and not use too much, is the ability to make text into images. It is very tempting to use special effects for text, and in doing that making the text into an image, but that makes the text unreadable for the search bots. Such effects should only be used for navigation buttons, special headings etc, not for the main text.
The navigation made as described above will also be unreadable to search engines, therefore it is recommended also to have simple text links e.g. in the page footer, that the search bots can read.
If you bear these hints in mind, there is no reason why a VSD made site should not be Google friendly.
Others might have more hints for you, these are the ones that came to my mind...