To configure a vlan on the 3750, do the following commands (these are the same on almost all of the Cisco switches, so if you wanted to create them on the 2950, use the same commands). In 'config' mode:
<b>vlan 2
name High-Management
state active
vlan 3
name Low-Management
state active
vlan 4
name Users
state active</b>
The VLAN numbers can be anything you want really, but there is no real benefit from using any other numbers, unless there are other vlans already, and these numbers are in use with those.
Then you need to add the user ports to the vlans. use the following commands for that
<b>interface fastethernet 0/1
switchport access vlan 2</b>
Change the interface numbe and the vlan number to whatever you need this to be.
To route between them, you need to create virtual interfaces for each vlan. The commands are
<b>interface vlan 2
ip address a.b.c.d
no shut</b>
do this for the other vlans, and they will route between them. Use these IP addresses as the default-gateways of the PCs on each VLAN. You can apply basic ACL to the VLAN interfaces, and so many of the same functions as with a router.
You can confirm the VLANs are working with a 'show vlan' command. You should be able to see the interfaces allocated to each vlan.
If you want the 2950 to also participate in the VLAN network, if there are users on it who are not 'High Management' then you can create a trunk between the switches and keep each VLAN separate.
I think this will get you off the ground with this project. Post more information, or questions here if you need some additional help.