I noticed that the eclipse version installed when following the instructions in the book was 1.6.1 whereas the Android ADT Plugins wanted 3.6.x.
When I went back to the eclipse web page There were direct links to the latest downloads.
You need to go to
http://www.eclipse.org/downloads/ and download the Eclipse IDE for Java EE Developers, (although the android developers site says the "Classic" eclipse is also ok).
Once I installed this, the ADT plugin installed easily. So far everything looks good but I haven't yet started any application development.
Basically it looks like the book was a bit too explicit about the download path and now points to a very old archived version.
Good luck