Hello Lennin,
Cisco switches can be configured to negotiate a trunk with neighbor using a protocol called DTP or to be trunk unconditionally.
I would suggest you the following configuration on the 3750 side
interface giga 1/0/x
switchport
switchport trunk enc dot1q
switchport trunk allowed vlan data_vlan_id, voice_vlan_id
switchport mode trunk
where x stays for the actual port number
data_vlan_id, voice_vlan_id stays for the vlan numbers you want to be permitted on the trunk link.
this still allows DTP messages to be sent or received.
I will check SGE2010P config guide if I find it.
Edit:
config guide for your linksys
http://www.cisco.com/en/US/docs/switches/lan/csbms/sge2010/administration/guide/SGE2010_AG_A-WEB.pdf
Edit2:
I suppose only one of the last 4 ports can be used to connect to the C3750.
you may need to create the two vlans locally on the linksys switch as it happens in Catalyst Express 500. (no VTP support)
Hope to help
Giuseppe