NOTE: Before trying to add any network printers, be sure to know what the printer's hostname. You'll need that information for later. You can find a full list of printer information here. Hostnames are also listed on the front of the printers. 

If you wish to use Duplex (2-sided) options, make sure to acquire the drivers for the specific printer.

For the HP printers, you need to install the printer drivers before proceeding.  Download this utility that will let you search for your specific HP model and it will download the printer drivers for you: 

After you download the HP Essential Software, click on Show in Finder.  Open the .pkg that Finder points out to you; It should be named something like hp_printer_essentials...

Follow the steps in the installer until installation is complete. Then proceed to the steps below. 

To Install a Printer on a Mac

1. Click on the Apple Menu and open System Preferences

2. Click on Printers & Scanners

3. Click on the '+' icon underneath the Printers list. Alternatively, you can use the '-' icon to remove printers that no longer exist or that you no longer use.

4. If you have the hostname for the printer, click on IP and enter the hostname in the given field.

4a. If you've installed the printer drivers, but it doesn't auto select for you. You can select Select Software in the 'Use' dropdown menu.

4b. You can use the search to select the printer model that applies to your use case. Then, click OK.

4c. If all the printer information looks good, then click Add

5. Check the boxes for Trays and Duplex unit. If you don't have an option for Trays, the printer is probably not equipped with an extra tray. Check the box for Job Storage if you wish to use HP's Secure Printing Feature. Then click, OK. 

The newly added printer should appear under the Printers list now Now you'll be able to select the printer when you need to print.