For me, on the iPhone, it was as simple as adding an e-mail account..
Go to Settings > Mail Contacts Calendar > Add Account...
Choose Microsoft Exchange.
Type in the Google e-mail address,
Domain is m.google.com
Username is the e-mail address
(there may be more on the "Next" page, but I don't remember what it is)
Immediately my contacts started coming over to the device, and now, even my calendar IMMEDIATELY syncs up. It's quite fantastic and I am very happy.
All of this information was given to me by the worker at the Verizon store.