Delphi is really an easy language. There are so many amazing libraries and components available for it. For keygening, it really makes a lot of things straight forward. You can inline assembly code into your application with the ASM tag. When I first learned delphi, I used the Delphi training series on youtube. These videos are a little dated now, but will give you a good basis for programming:
Code:
https://www.youtube.com/watch?v=6K1VxF13L80&list=PLCC32444ED145541B
Since turbo delphi is no longer available, you can just use this series with Rad Studio.
Delphi Basics is also a good site to read more about the language:
Code:
http://www.delphibasics.co.uk/