I've never tried attaching a tablet/phone to a printer, but the computers should be easy. I'm assuming they are all Windows?
Computer with Printer attached....
Hold down the Windows key (Start key on KBD) and tap R
A 'run' dialogue box will appear. Type
cmd
into the box (command on a seperate line to aid reading) and click OK.
A black box will appear, enter the following command
ipconfig /all
A load of text should appear in the black box.
You will probably need to scroll up in the black window. The first entry should be 'Host Name' after which there should be the computer name. To make life easier, lets say it's called 'PC-Print'.
On the computer without the printer....
Hold down the Windows key (Start key on KBD) and tap R
A 'run' dialogue box will appear. Type
\\PC-Print
Click OK (Replace PC-Print with the name of the computer got from the previous step).
All going well it should show a window with devices shared on that computer. If it does, a printer should be listed, if you use the right mouse button and select 'connect' it should install the printer. It may ask for drivers, especially if this PC is running a different version of Windows to the printing PC.
This should work with a few exceptions, such as Windows Firewall issue, permissions issues or mismatched workgroups.