You need to configure VTP for VLAN management between the switches, you need a trunk between the 2 switches. You need to configure layer 3 interfaces on the 3550 to handle the interVLAN IP traffic or pass this up to a router with ethernet sub-interfaces. You need to configure a default gateway for your internet traffic.
Knowing all the above how can we configure the connectivity between CAT 2948G and CAT 3550 PWR (knowing that is already connected to Internet) . Only servers/workstation connected to 2948G cannot connect to Internet.