This can (and should!) be saved on your computer and your iPad.
b) As a free iBook once you download the free iBook app from the iTunes App Store.
c) Online using the link provided in the Safari favorites on your iPad.
The answers to many questions, especially if this is your first Apple mobile "iDevice", can be answered by spending some quality time with this handy document.
Since you are in Austria, you can download the manual in German if you prefer -- Apple Support; Handbcher