Hubs vs. Cabling

you can get 100MB with correctly installed cat5e. you need cat5 rated wall jacks and patch panels also strictly speaking. i think the e is distinction for network as other is rated for telco. possibly stuffed with baloney on this point. you need cat6 (e?) to go to gigabit rate. hubs rated speed only, not 'cat' type rating. hubs have to be able to go to 100MB also if that is your goal. if you have some old and some new stuff get multispeed hubs (10/100). remember if only using network to share internet that 100mb speed is wasted. fast t1 connection only 1.5 mb, way slower than 10mb. also note wireless rate may be much slower than 10mb.

Cat 5:

Supports 10/100 Ethernet (100MBit/s maximum)

Cat 5e:

Supports 10/100/1000 Ethernet (1Gb/s maximum)

Hubs:

Doesn't perform routing.

Any incoming network packet is broadcast on all ports on the Hub.

Only 1 packet at any one time on the Hub.

Performance on hubs degrade very quickly in high network utilization environments.

Switch:

Layer 2 Routing device (OSI Model reference). That is routes based on destination MAC Address.

Learns the MAC Address of all connected devices.

Only transmits packet on the port with the correct MAC address.

CAT V cable is rate to 100MBS and CAT 5e is rate to 200MBS. You want 5e for full duplex hubs and switches. Both can have a maximum distance of 300 ft through no more than 3 hubs (suggested). The 300 ft is the maximum end to end run of you network from server to client. To exceed 300 ft you need a repeater (hubs are NOT repeaters) or go fiber. Cat V cable should be used from hubs to clients, but generally not used as your 'backbone' ie hub to hub (unless they are fairly close and on the same level) between floors and/or bldgs I would switch to fiber as a backbone.