The easy way is to get a print server and connect the printers to the print
server. Some new printers even come with them built in. The print server
connects to the router either by cable or wireless and then you setup the
printer with IPP so that it prints to a static IP address. The bonus of this
is that it works without going through another computer so it is
independent. Mine works beautifully in Linux. You can get them for under
$50. I bought mine on sale for under $20.

Someone else will have to advise you on printer sharing with Samba and on
Linux, as I have never had the need (or desire) because this just works so
easily.

Are the printers located where you physically want them, and are the PCs
running at all times when you need to be able to print?

Sharing your printers via CUPS is a fairly straightforward solution, if the
PCs are on and located where you want them.

If you need different access (e.g. one PC is often off when you need to
print), a dedicated, always-on print server may be better. You can still run
CUPS on a dedicated box.

Ubuntu can manage CUPS printers, or you can manage them via a web page from
anywhere on the network.

There are two steps: first share a printer, then use a shared printer.

In Ubuntu, you go to Administration/Printing on the host computer as your
starting point to share a printer. (This might have moved around from version to
version.) After a click or two you give it a name, and you're done.

In Windows, it's Control Panel/Printers. You also have to ensure that File and
Print sharing is enabled in the network properties.

To use a shared printer in Ubuntu, begin at Administration/Printing and select
"new," network printer. With any luck, Ubuntu will discover the printer(s) you
want and it just takes a couple of clicks to install it or them.

This somewhat depends on how good the vendor's support is for Linux. For
example, a couple of years ago, it was almost impossible to get any Lexmark
printer working, but Lexmark has turned 180 degrees in its Linux support.

I have a Brother laser printer attached to my router, and installation on Lucid
or Maverick takes about three clicks.