Is there somewhere published a PDF of the Language Reference? I want to study it: it is so slow to keep looking up references which at a guess can fill one's needs, during programming . . . . OR can it be somehow downloaded from the website?
C-PLUS-PLUS (link) is an excellent site with clearly written code for every element of the language.
It's not a tutorial , so you may regret your question - but I use it every now & then for a quick check on function syntax.... it's never let me down.
I doubt you can print the whole site to a PDF - it would be many thousands of pages... perhaps email and ask them.. !?!
Actually cplusplus.com does have an excellent tutorial: http://www.cplusplus.com/doc/tutorial/
You have to skim over some parts that don't apply to Arduino but I found it extremely helpful. That site also has a good reference.
That site also has a section of user contributed articles which I found to be of inconsistent quality. I wouldn't spend much time in that section until you have enough general knowledge to be able to evaluate the quality of the information provided.