Need help to add duties to HP enterprise network

[jwhiteker]

Needing help with an enterprise setup.  I set up a robust network at my small church.  I'm using an HP MSR20-21 router and (3) wireless HP M220 AP's all on a single VLAN.  It's working great, however, I need to now establish a "guest" network for internet access only while keeping the current wireless intact for staff.  I'd like to also add some level of QOS priority to our existing network for employees and hide the SSD.  

So, do I need to create an additional VLAN for the guest network, or can I just start a new wireless community on these AP's with it's own settings?  My next problem is that I placed the three AP's in a cluster so no one loses access as they roam our building.  Now that we're doing a lot of streaming and uploading on Sunday mornings, we need our internal devices to have the biggest share of bandwidth to complete our tasks.  I also only have a single internet connection to work with.  Please help.