There is no need to export images to a folder if you intend to use Blurb.
My procedure for a book is this-
1. Select the images I want in the book. (You can use flags, stars, any method, if you want)
2. Create a standard Collection, adding the selected images.
Hint: You can make this new collection the "Target collection" and thereafter press 'B' to bounce more selected images into the Target Collection. (This will only be a temporary collection)
3. With all the images for your book in a standard Collection visible on the screen, select them all [CTRL+A] and goto the Book Module. [CTRL+ALT+4]
4. Start Designing your book. (Set book size early!)
5. At some time early in your design work- click on the TAB to "Create a Saved Book". This will create a new "Smart (Book) Collection" that will be automatically updated as you work to capture, preserve, and show all your design work.
6. Send to Blurb.
*In future you will ALWAYS re-open your book design by clicking on the white arrow that appears at the end of the "Smart (Book) Collection" named in the collections panel.
* To add more images to the book, drag them from the Library grid onto the "Smart (Book) Collection", they will appear at the far end of the filmstrip in the Book module.
* You can make a copy of the "Smart (Book) Collection" for different versions of a book, or use your design layout with another set of images. [Right-click > Duplicate Book] Maybe make a Duplicate if you need to do a major change to a book design and you find you need to go back to the 'original' (eg. Page size change)
...OK, that will work, but I still have to go through, via either filmstrip or in library, all of my images one by one...which I suppose I would have to do anyway...sheesh. Thanks for the response and, more importantly, the terse workflow...much appreciated...