[MovedGoalPosts]

Sounds like your office is not that much different from mine, maybe a tad smaller.

I think the telling thing is your intent to upgrade one day to a SBS based network. That guides what you need now.

Simply put you need a cable to each workstation, router, and standalone network devices such as printers. If your printers are going to be attached to PCs then only one network port is needed.

Your network needs to be joined at the centre with a managed switch. This needs at least as many ports on it as there are ever likely to be computers or other stuff attached. A managed switch has a better ability to avoid "clashes" of data around the network, so will run faster. Most switches wil at least offer 10/100 speeds, and some have Gigabit available. The switch should auto sense the speed and also if the connection is full or half duplex (uses all eight or only a few of the CAT 5e connectors). Typically printers only run at 10 speeds whilst modern computers will do 100 or 1000 connectors. Thus the managed switch will sense and allow fast file transfer but slowere ptint data movement.

Realistically, our network operates at 100 speeds for file transfer, quite compfortably with 20 PCs. The most I might consider, given the costs, is a gigabit link from the server to the switch, anything else may be underutilised, and limited by the speeds of your server or other hardware.

If you think you might need a cable in the future, put it in now. The extra cost of pulling two cables compared to one is not a lot, while doing it at the same time, and tearing your office apart. Adding cables later can bump costs due to the disruption.

I know nothing about VOIP, so don't know what that might need but extra cables is most likely.

If thinking of SBS2003, consider that the preferred network setup is for the server to have 2 NICS (thus two network cables), one to the LAN switch, one to the internet router. You may also want to use the shared fax facility, meaning a phone line needs to be near the server too.