'How to Draw Manga Vol. 1' has been translated into English. I have it here in front of me (it's in the Viz Shop-By-Mail catalog)...
ISBN: 4-88996-042-2 UPC: 9-784889-960426
Publisher: Graphic-sha Publishing Co., Ltd. 1-9-12 Kudan-Kita, Chiyoda-ku, Tokyo, 102-0073 Japan
Distributor: Japan Publications Trading Co., Ltd. 1-2-1 Sarugaku-cho, Chiyoda-ku, Tokyo, 101-0064 Japan
I'm going to be doing a review of it at some point for
www.j-pop.com, and Julie Davis did a review of it for ANIMERICA awhile back. I don't know if we currently have any copies in stock