Congrats and on behalf of all cat owners (well, cat staff) and cats everywhere, thank you for doing this!
Puma has summarized in a couple of posts what it's taken me over 10 years of having a cat to learn.
Good advice all around.
And re: the brush - our guy LOVES to be brushed, and we got him started on it early. It's grooming but also a form of interaction and attention which he loves. How much? A friend was looking in on Bruno (Brunello) daily while we were on vacation, and decided to brush him until Bruno walked away. THIRTY minutes later, our friend gave up! But Bruno was very smooth.
Good luck with the new additions to the family!