question about updating ethernet connection on our school

[alienhead]

for the start let me just tell you what kind of ethernet connections we have now and what i want to have. On the main school building is the main server and from main server is connected to ethernet\optic converter so optic is connected from one to another ethernet\optic converter. then from converter is connected to switch and from this switch is connected to another three for every floor. We have a big trouble of IP conflicts and there is no security but it should be. Now we must find the solution and tell it to the main teacher witch is responsible for that. We already have new server and we are thinking about getting router if that will be necceseary. We want to get with update next things: there must be working "obtain an IP adress automaticly" option. And there will be very ql if on one floor there will be IP's from lets say xxx.xxx.xxx.1 to xxx.xxx.xxx.50 and on another floor from .50 to .100. And if someone know about getting up the server station and witch software is required. If anyone is ready to help and has MSN messenger you can add me by adding the adress "tomi307@hotmail.com". Thank you very much