I have a question regarding one network I am supposed to build and administer. It should be put in a building that has 23 floors, of which around 10-15 will be connected. Every floor will have 20-50 computers connected, which are separated by walls. Each of the wall-separated groups include 4, 8 or 10 computers and there are at most 5 groups per floor. There is a possibility of devices like printers to be connected, but that is not important right now. The computers will be primarily used for file-sharing, possibly some gaming (Counter-Strike-alike games). Some servers might exist on the network (HTTP, FTP, mail server), but that is not a requirement.
I have built small networks with around 10-20 computers, but never a network of this size. I am sure that there are some problems that I am not aware of, so I would like to explore this in depth. Does anybody have links to some tutorials on the Net about how to make such network? It should address possible problems that do not happen (or are not a problem) in small networks.
Here is a solution that I am thinking of. I would put enough 8-port (for small computer groups) or 12-port switches (for bigger computer groups) on the floor, depending on how that floor is about to be connected (not every computer should be). I would put two or three switches on some floors which have 16 or 24 ports, so every of 10-15 floors would be connected to them directly. A scheme would be:
Legend:  - Group of 4, 8 or 10 computers n* - n-port Switch (e.g. 12* - 12 port switch) MFS - To some of the main-floor 16- or 24-port switches
Example floor (with 26 computers):     | | | | 8* 12* 12* 8* | | | | MFS---/ | | | | | | | \\---------/ | \\-----------------/
All other floors would be connected in the same way, so MFSs would have say 40-60 places occupied in total. Some of MFSs would be used as a central gathering point:
MFS1---\\ | MFS2---+--- *(possibly)* ---Router----Internet | MFS3---/
It would be possible to connect this network to a broadband Internet link, using a router connected to MFS2, as pointed. What do you think about this? Any problems with this? I am concerned about the possibility of a broadcast storm. Is this a problem? How could be this avoided e.g. by using routers? As I found out, using routers would prevent users from using file-sharing (at least using Windows machines). Is this true and what is the solution?
Help is VERY appreciated.