Question : Catalyst 2948G <---> Catalyst 2900XL  Trunk  VLANs

What steps do I need to set up a trunk between a 2948G and a 2900XL that will carry VLAN 2 and VLAN 3 traffic?

Answer : Catalyst 2948G <---> Catalyst 2900XL  Trunk  VLANs

The Cisco site has a great reference at:
http://www.cisco.com/warp/public/473/25.html

Basically to configure an ISL:
1)  Connect the 2948G and a 2900XL with a crossover cable
2) On the 2948G:
   a) If you want routing to occur set the bridge irb command
   b)  Configure the isl with the encapsulation isl X command
   c)  If you want bridging configure the bridge-group and the BVI interfaces
   d)  If bridging set the STP and allow Network protocol routing using bridge X protocol XXX and bridge X route XXX
3)  On the 2900XL:
   a)  Add the VLANs to the VLAN database using the vlan database command
   b)  Set the switchport mode to trunk on the trunked link
   c)  Set the switchport acess vlan X for all vlans