Configuring IPSecRouter to PIX (a good example for both endpoints): www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_configuration_example09186a0080094498.shtml.
PIX Firewall Command Reference, Version 6.3: www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_sw/v_63/cmdref/index.htm.