Hope your Fusion class wasn't as much of a waste of time as mine... I took the class about a month before they began using the SSI modules, and even knowing that was coming down the line, they only alluded to changes coming and didn't cover it at all.?
Not that you asked...?
In any case, you'll want to add one Fusion Room definition to your program for each physical room in your program, and then connect that to a unique set of SSI modules for each of these rooms. Keep in mind, you'll also want to designate the only one of your SSI modules as "Primary_SSI" in the parameter settings. I also tend to set "Prefix_GUID" and "Append_Program_Slot" to Yes, since I sometimes run a single compile in multiple program slots for different rooms. Crestron's documentation isn't great on this, but you'll want to make sure the "Fusion_SSI_ID" and "Scheduling_ID" are unique to each SSI instance, since they are tied to crosspoints internal to the module. If you've attempted a compile, though, you've likely already found this out for yourself.
If you're already implementing multi-Fusion Room support from a single processor, you may be interested in this bit of information. If you're implementing the Scheduling Awareness module, you can't support more than ten rooms from a 3-series processor. Fusion Support Group admitted to me that they hate the Scheduling Awareness module and how bloated and processor-intensive it is, but they also said it isn't a development priority. So, ten rooms it is. If you're not using it, you can get more like 15-20, but they wouldn't give me a hard and fast answer on that. This is with a 3-series processor, mind you. I wouldn't try it with a 2-series.
There's more information to be had on multi-room support from a single processor, but I won't bore you with the rest unless you think you'll have use for it. Good luck!