It sounds like you changed the management vlan 1, which (if true) is why you lost the communication from the other switches. By default, vlan 1 is the management vlan for all Cisco switches and all vlans. Of course, you'll need a (CISCO, is there any other :>) router to get to the other vlans. Remember also, switches are layer 2 devices and do not understand IP (layer 3) addresses. It does use an IP address (telnet management) but that's about all.
Frank