Updated: May 29
A list of torque specs for most things including the engine... If you're gonna do it - do it right!
The correct torque is especially important on cast aluminium engine components with steel fasteners - Most of these things aren't as tight as you might think if you were tightening them by feel and it's incredibly easy to strip aluminium threads with an overtight steel bolt. The hot side of the cylinder head around the exhaust manifold is a prime location for this happening.
Always clean bolt heads & exposed threads with a wire brush and WD40 before tackling them. If you can - wherever you have a steel bolt screwed into an aluminium thread, give the bolt a single tap with a hammer before undoing it to shock the thread free. If it gets tight whilst you're undoing it, screw it back in a turn or so then back it out again slowly to avoid snapping the bolt. Plenty of WD40 and take it easy.
The following torque settings are quoted from a popular range of workshop manuals; it's not a comprehensive list but hopefully it'll keep you right for basic servicing tasks. Most bolts around the engine are 10, 12, 14 or 17mm.
Key Service Items:
Wheel Nuts - 100Nm (OEM)
Sump Plug 14mm - 30Nm
Spark Plugs - 25Nm
Coolant Drain Plug - 20Nm
Ignition Coil 10mm Bolts - 10Nm
Lambda Sensors - 44Nm
Clutch Plate Bolts - 19Nm
Caliper Guide Pin 13mm Bolts - 30Nm
Carrier 17mm Bolts - 89Nm
Disc retaining T30 countersunk bolt - Pinch tight! Make sure its easy to undo this again.
ARB Droplink Nuts - 18Nm
Driveshaft Hub Nut - 216Nm
Wishbone to Subframe Bolts - 100Nm
Ball Joint Nut - 98Nm
Suspension Damper Top Mount Nut - 55Nm
Suspension Strut Pinch Nut/Bolt (hub) - 48Nm
Track Rod Balljoint - 33Nm
Track Rod Adjusting Nut - 47Nm
Rear Beam Axle to Chassis - 123Nm
Rear Hub to Trailing Arm Nuts - 60Nm
Lower Damper Bolts - 48Nm
Top Damper Nut - 25Nm
Cam Bearing Small Caps - 13Nm
Cam Bearing Big Double Cap - 15Nm
Camshaft Sprockets - 47Nm
Inlet Manifold Nuts/Bolts - 30Nm
Exhaust Manifold Nuts/Bolts - 24Nm
Fuel Rail - 27Nm
Stage 1 - 32Nm
Stage 2 - Further 180 degrees
To Engine Block - 64Nm
To Lower Plate - 40Nm
Small Bolts - 10Nm
Big Bolts - 24Nm
If you're doing anything major I'd really recommend picking up a Haynes manual for its comprehensive torque and clearance specifications.
The specs here refer to the first-gen '05-14 cars.