Don Guyot's pamphlet Suminagashi, an Introduction to Paper Marbling is available from Colophon Book Arts Supply, which also has some great suminagashi supplies. This is filled with great information.
Suminagashi: The Japanese Art of Marbling : A Practical Guide by Anne Chambers is quite good, with information gleaned from a number of experts she met in Japan.
The Ultimate Marbling Handbook by Diane Maurer-Mathison has a very informative chapter on Suminagashi as well, with information on making double prints, among other things.
The Ultimate Marbling Handbook by Diane Maurer-Mathison has a very informative chapter on Suminagashi as well, with information on making double prints, among other things.
The Little Book of Book Making by Charlotte Rivers has a short chapter by Ruth Bleakly with instructions and a few great tips.
Add the information in all of these books together and you'll get a pretty complete overview of most everything you'll need to get started with you own experiments!
Other than that, there is the rare art book Suminagashi-Zome, a translation from Tokutaro Yagi's Japanese instructions, published by the Heyeck Press in 1991. Unfortunately, it is a pretty expensive and hard to find tome. I've got my eyes peeled!
I've been experimenting with so many different things- types of paper, different inks, double dipping, printing on both sides... The list goes on! I'll have to tell you results and what I think I've learned a bit later. In the meantime, the pieces pictured here are just a few examples of what I've done so far.