Growing network, need advice on VLANS

Hi Everyone!

I work for a small private school. I support about 500 staff and students. I need some networking set-up advice. I've been reading up on VLANS and think I need to implement them.

I inherited a network, 10.0.x.x subnet 255.255.248.0 running about 460+ devices on average.

I have a mix of wired and wireless clients. My 9 switches are HP ProCurve 1810G-24s. I have 12 Meraki APs that provide my wireless coverage. We are connected with Comcast that feeds into my filtering server that feeds into my switch.

I'm trying to get our crappy phone system replaced with a VoIP solution to reduce cost. That is going to add about 35 devices to my network. We added over 100 devices last year alone. I'm worried my broadcast traffic is congesting my network at this point.

Thanks for your advice!