Hi nvictor,
I'm a Software Engineer and a PhotoReader, and I don't think you should mindmap referencelists. What you want to go for is the basics of a language, such as objects, variables, the structure of functions, pointers, references, inheritance, OO design, etc. Mindmap the core ideas of the programming language, and branch those out on your mindmap. Mindmapping is not very useful for listing functions; you should use it for concepts instead. Besides, learning a popular OO-based programming language is not that difficult - once you get the basics. C# is based upon Java, Java is based upon C++, etc. There are some small differences in the structure of the language and the use of memory, but other than that, once you get the hang of it, learning a new language shouldn't be difficult. I still need to reference the JavaDoc or the MSDN libraries from time to time, because there are so many classes out there with so many functions, it would blow your mind to remember them all. It can be done, but what would be the benefit? What would be the purpose for remembering all of those functions? You don't need to remember them all to program efficiently, trust me. I think it's better to focus on learning how to design your software and learn the basics with PhotoReading, and then start practicing in the real world. You can read about a language all you want, and understand it, but you still need to program it!
The same saying goes for Design Patterns by the way. I'm in my final couple of weeks now before I'm going to graduate, and I know many people in my class who still don't understand the basics of programming completely in a practical way; even through they've completed many projects over the past couple of years. You've got to walk the talk, practice what you learn. PhotoReading definitely makes learning a programming language easier, but don't substitute it for applying your knowledge. That's just what I wanted to let you know.
So in short, mind map the important language characteristics. You will find them throughout the book(s) you PhotoRead.