What to do?

The general manager of our of our companies decided that he was tired of his computers breaking down every 2 years (viruses/malware infections of his own doing) and decided on the advice of his business associates to switch to a Mac. His existing laptop was hooked up to a docking station w/ a 22" monitor and network connections. When away from the office, he uses a wireless card to connect to the internet. I nave not worked with Macs and don't know how it will interface with the existing network and any shared files he may need to access, network printers, etc. There is only me handling IT issues for a half dozen small companies. I guess my question is whether to just keep my mouth shut and start learning how to make a mac work in a microsoft environment or what? I assume a Mac can't join a domain so how are permissions handled?