Extended Star Topology

Rather than having a central switch in the department connected to other switches to make up the required number of ports, you could stack switches. The 3Com Superstack range does this well, as do the Cisco ones. By connecting the individual switches together using stacking cables (which you'll have to get from the manufacturer) you effectively combine them into one big switch and you don't need individual uplinks or crossover cables between them

would using the 3com super stack range of switches and connecting them together thus eliminating the main switch, would that not great either big broadcats or collision domain?

No bigger than by using individual switches and connecting them together yourself. Switches forward broadcasts anyway, so if you create (say) a network containing three switches by stacking them it will be the same in broadcast terms as a network made of three switches where you do the uplinks yourself. In terms of collision domain, the whole point of a switch compared to a hub is that a switch breaks the collision domain up into many smaller segments. The stacking interconnection between switches is just a means of interconnecting the switch fabric on each switch, so the stack-of-three-switches can make switching decisions across the whole width of the port fabric.
I would have said stacking is the better approach because:
1) You'll lose a few available ports by doing the uplinks yourself
2) The inter-switch stacking connections usually provide greater bandwidth than a port-to-port connection
3) The arrangement is likely to be more efficient in its handling of traffic
4) Depending on the manufacturer you often get management advantages
It all depends on the size of your network really. With a small network of just a few switches there's little to choose and either approach will work just fine. However as the number of switches involved grows larger the advantages of stacking them become more significant.
What does everyone else think?

i thik that sounds like a plan to me Bishop, i'll go with super stacking them, thanks for all your help and advise, i hope to stay on here and help others with my wisdom, if i got any that is lol.

one last question, i am going to use the 3com superstack range but only for stacking up in the individual departments that reuiqre more than one switch, in turn there will be one swtich from each department connected to one main switch then onto the router, i will use redundant connections coupled with a gigabit ethernet full duplex link between them, but oin what way is it best to connect them or should i say how should i connect them, like with straight through or crossover or can i use fiber optic or something?

No problem