Ummm.... when I went to school it usually was the librarians who take care of the PCs. Have you simply tried asking someone if you could play with the network, kiddie? Im sure if the peaple in your school really wanted you to play around with things like telnet then they'd tell you how to do it. Most computer rooms in schools have a bunch of PCs hooked into one another with nodes like printers right? Since you have all this tech around you then you should already have 'access' to the network.
Im sure the real meaning of this thread was... "How do I break into PCs so I can sub7 the entire planet?"
And as for all the DOS related things in this thread..... don't schools usually run MACs most of the time?
How to access a network ? ... its very easy - you enter the username and password that the system/network administrator gave you ..... you don't have these ? ....then there is probably a very good reason - they dont want you on their network !!
School may suck but no where near as much as jail does.
I dont think you are going to get any help here, for your own sake - delete this thread.