How to effectively manage a new collaborator? As a 3rd year PhD student in a Canadian university, I've been given the opportunity to work directly with my supervisor's long-term collaborator, who is a young faculty member in an Australian university. I shall be visiting him for a month to initiate a (STEM-theory) project and am looking for advice on how to make the collaboration fruitful.

More specifically, it took time for me to understand my own supervisor's priorities, strengths-weaknesses and way of working. With that understanding, I have been able to work effectively with him. How can I quickly learn the best way of working with my new collaborator?
I just wanted to comment that your choice of words in the question is somewhat inappropriate: you do not "manage" a new collaborator when your collaborator is more senior than you are. As a graduate student, you cannot have any reasonable expectation of asking for and receiving commitments from a professor—if anything, it's the other way around, even if you will be the one doing the majority of the work!

However, this also tells you something about how to handle the process. Remember that the professor is quite likely to have many more time commitments than you will. Therefore, you will need to be cognizant of that when making plans. What takes you a few days of effort may take your collaborator substantially longer, if he has to do it himself. So it may be very useful to find out if there is another point of contact you will be working with in the other professor's laboratory group, and ask if you can coordinate things directly what that individual.