Most of the 2960 switch models (except the WS-C2960-24TT-L and WS-C2960-48TT-L) have a GBIC/SFP uplink port that supports Gigabit Ethernet Small Form factor Pluggable (SFP) connectors. The list of compatible connectors for the 2960 series switches can be found on the following data sheet:
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/product_data_sheet0900aecd80322c0c.html
You need to ascertain what type of transceiver the service provider is using and match it with a compatible one at your end. In addition to the single mode fiber specification, you need to know that it is Gigabit Ethernet and the power level (related to transceiver type - LH or ZX).
If your service provider is delivering 100 Mbps Ethernet over single mode fiber (100BaseFX), then you'll need to convert it to copper using a transceiver external to your switch. You'll need a third party product for that. Take a look, for instance at Transition Networks' products. The following page shows what you'd need: http://www.transition.com/TransitionNetworks/Products2/Intersection.aspx?Definition=Stand-Alone+Converter&Topology=Fast+Ethernet
With respect to your second question, trunking from your switch to your router should be fine. You need to consider at what point you are going to insert firewall or other type services (i.e, NAT, etc.) to protect your internal network.
Hope this helps. Please rate helpful posts.
