As a rule of thumb, unless the fastener is specifically mentioned in the torque tables in your manual, the following are the ISO standards for 8.8 fasteners (which most steel fasteners are)
M5 - 6Nm
M6 - 9Nm
M8 - 23Nm.
That'll cover most "general" fasteners on the bike. Check to see if there is a specific torque listed first, but if not use the general settings. They do assume fasteners/threads in new/good condition and greased. Not bad practice though
