Hi
Tanya, sorry I don't know the tutorial you are referring to.
First off, what type of map are you scanningand what size?
Is it a street map, OS relief map, political map, local area map, surveyors map, pirate treasure map,

etc?
How many colours, tints or text are in it?
How fine is the detail and what condition is the original?
What is the final size and resolution of your print.
(To see if it is possible to re-assemble the 8 scans into one file.)
Are you scanning and printing each panel individually without any Photoshop matching?
If the map is too big to composite and print from Photoshop, you could try matching two adjacent panels at a time then print after matching.
You should be able to match each panel with an Adjustment Layer if you use the same scanner settings to scan the panels.
You will find it easy [bustagut] [bustagut] [bustagut] if you have a good margin for overlap, a soft edged mask along the edges helps hide the seam.
Cheers, Al.