For Germany and the surrounding countries, THE best cycle tour book/map that you need are those produced by BikeLine
The two books you need are
http://www.esterbauer.co.uk/db_detail.php?buecher_code=R1
http://www.esterbauer.co.uk/db_detail.php?buecher_code=RHE4
If you buy them via Amazon double check the published date, as often the old versions are sold here.
Whist the actual book is in German, it is NOT a requirement to be able to understand German. as the main thing you want are the highly detailed maps.
The BikeLine books have a list of all the accommodation, section by section, from camp sites, to B&B's, to 5 star hotels, all of which will be cycle friendly.
(You will see lots of 'Bett und Bike' signs on German B&B's/Hostles/hotels)
There is also a section on things to see and do, alternate routes and local history, which it would be nice to read if you can understand German, but not essential
It also shows where the local towns Tourist Info Centre (TIC) is.
We have done a lot of cycle touring in Germany (we dont speak German)
We mostly B&B it. We just rock up in a town late afternoon, go to the TIC, and ask them to find us a B&B from the 'Bett und bike' list. B&B sorted!
If no TIC, then we look it up in the BikeLine book and knock on doors or send e-mails earlier in the day
All the newer BikeLine books come with a downloadable GPX track, so if you have the equipment you can simply follow the route electronically
If you have not done cycle touring before in Germany using the BikeLine books, you also need a Handlebar bag with a transparent map pocket on the top.
After a day or two you will master the art of riding and reading the map at the same time
FYI - We have over the years tried other cycle maps/books/guides Cicerone etc, none are as good as the BikeLine ones, even despite the language issue