I tested a few of these and this is what I learned...
From top to bottom in the images, the full model numbers with hardware versions are the following:
Netgear ProSafe GS724AT V1H1
Netgear GS724TP V1H2
Netgear ProSAFE GS748T-500NAS V5
The first step when testing most used IT hardware (and you'll notice I seldomly work with anything new) is to set it to the default factory settings. This ensures a software problem doesn't present as a hardware problem. For some devices it's easier said then done. In the case of this stack of various Netgear Managed Switches, I went to the Netgear website and grabbed a pdf manual for one of them and the instructions did not work. I should have just done what I usually do and google the switch model number and look for someone who actually reset one of these before. Here's what I found that worked.
Plug the switch into a power source
Attach a network cable from a PC to any one of the ports on the switch
Press the "Factory Defaults" button using a paper clip and hold it for 3 seconds. The link lights should flash. Wait for link lights on your port to light up again and then continue.
When resetting the Netgear GS724TP V1H2, I had to press the "Reset" button with a paper clip following pressing the "Factory Defaults" button for the switch to boot up properly after the reset.
Once reset, the switch will have an IP Address of 192.168.0.239 and a Subnet Mask of 255.255.255.0. The IP Address assigned to the managed switch as a default was the same for all three of the switches, so it will likely work with similar Netgear hardware.
Now that you have the default settings, you'll have to take some special steps to connect to the managed switch in order to modify the settings. The below steps worked for all 3 Netgear switches that I tested, so it will likely work for more models.
Connect a PC to one of the ports on the switch making sure nothing else is connected to the switch.
Change the Network Settings for the Ethernet Connection on the PC and manually assign the following:
IP Address: 192.168.0.5
Subnet Mask: 255.255.255.0
Open up a browser on the PC and go to http://192.168.0.239
Log in with the default password of "password".
From here you can change whatever settings you need on the managed switch including changing the password ("password" isn't the most secure option) and setting up VLANs, etc.
Now that you have the default settings, and you're connected to the switch, you might want to test the ports before you spend too much time setting it up. If you ever made the mistake of fully configuring a device only to find out one of the ports is bad, you'll understand why. With an unmanaged switch you can just plug the switch into your network and plug the other end into your device and BAM! it's on your network and you'll be able to ping other devices. Unlike an unmanaged switch, a managed switch will usually not work that way without some sort of configuration. Here's what you can do to avoid that step and get right to testing the ports.
Plug the configured PC into the first port you want to test on the switch
Open up a command prompt and type in "ping 192.168.0.239 -t"
This will start a continuous ping of the switch. You want to make sure you get a ping response. Once you get a response, you'll know the port is good. A successful response will look something like this: "Reply from 192.168.0.239: bytes=32 time=58ms TTL=49"
Once you see a similar response, unplug the ethernet cable and move to the next port. I have had switches take 3 - 30 seconds long to reply to a ping the first time after switching ports, so be patient.
This isn't foolproof. I have had ports work intermittently, but it's a good quick test to give you a little piece of mind before getting it set up the way you want it.
I hope this helps anyone just trying to make sure their stuff works before a return period is over or something along those lines. The actual config can get very complicated depending on your needs, so read up and go nuts personalizing this bad boy!