Glendale PD uses 2 main channels that aren't encrypted, one for North and one for South. I would suggest programming both of them in and you can listen to the whole City or just the area you're in. I live just inside the Phoenix limits and work in Glendale, so I have Glendale and the local Phoenix PD precinct programmed in. Unfortunately Phoenix encrypts it's emergency traffic, but you can still hear a lot of interesting stuff.
Phoenix Fire dispatches for almost all of the valley cities and towns, so if you listen to dispatches, you get everything not just Glendale, but most of the response channels or talk groups are set up for different areas, so you can just enter a few and listen mostly to Glendale responses. The area fire departments use old analog channels for fireground coms and trunked digital for medical coms. The digital traffic can be monitored pretty much anywhere in the valley, but the analog traffic does not use repeaters, so you can generally hear things only a few mile away.
You can get an idea of Phoenix area talk groups by checking out the RWC page at :
Regional Wireless Cooperative (RWC) Trunking System, Phoenix, Arizona - Scanner Frequencies
It can be a bit intimidating, but people on here are willing to help.