This how to shows how to setup Etherchannel links between two switches. A trunk link was first established between the two switches and then the Etherchannel links were created using the PAgP protocol. You can download the PacketTrace file from here.
The following commands will create a trunk between the two switches. You can run the command on only one switch.
switchport fastEthernet 0/1 switchport mode trunk switchport trunk allowerd vlan 1-99,150 #in case you have VLANS
The following commands will need to be run on both switches.
interface range fastEthernet 0/1-4 channel-protocol pagp channel-group 1 mode desirable
The following modes are available.
channel-group 1 mode ?
active Enable LACP unconditionally
auto Enable PAgP only if a PAgP device is detected
desirable Enable PAgP unconditionally
on Enable Etherchannel only
passive Enable LACP only if a LACP device is detected