Where can I find a list of common faults?
http://uk-mkivs.net/forums/thread/931748.aspx

K03s upgrades
What do i need?
You should need just the new turbo and a K03s turbo intake pipe
http://uk-mkivs.net/forums/thread/921159.aspx

Exhausts
Which one?
The exhaust choice all depends on what you want from it.
Milltek seems to be a good all rounder, not too loud until you accelerate.
http://uk-mkivs.net/forums/thread/880356.aspx

How to tell if the engine temperature sensor needs changing
If you temperature sensor is on its way out, you will find that the temperature sender does not always sit on 90c, and that your MPG will be lower than normal

Where to find the engine temperature sensor
The sensor can be located on the right hand side of the engine.
Some good details here: http://uk-mkivs.net/forums/thread/980497.aspx

How to change the engine temperature sensor
Make sure that the car is cold (best to do it in the morning), and have more coolant ready incase some of it leaks. Its as simple as unplugging the old part, and plugging the new one back in
Some good details here: http://uk-mkivs.net/forums/thread/980497.aspx

Where to find the MAF sensor
The MAF sits between the airbox and the engine itself

How to tell if the MAF sensor need changing
Your MPG will be lower than normal, you car may not pull very well over 3k revs

How to change the MAF sensor
Unscrew the housing from the airbox, then release and move the clip on the opposite side of the MAF, then simply remove the pipes from the MAF housing and remove

Changing clocks
If you change your clocks, you will also need the mileage recoding onto them. This can be done using VAG-Tacho

Lowering over 40mm
If you are lowering your car over 40mm, you will most likely need to replace the front ARB. This is due to it catching on the driveshaft when going over bumps. This can also happen when you are on a full lock when turning.

Aero Wipers
Aero wipers replace your standard wipers. They have more pressure points on them resulting in better wiping. You can both complete kits including the arms, or you can buy just a conversion kit which replaces the blades

Diverter Valves
Most people recommend using a recirculating diverter valve as the Golf relies on excess boost pressure being put back into the intake system. An example of this is a Force 007P Valve

Loss of Boost pressure
If you have no boost pressure, it could be caused by a few things. These could be a faulty MAF (see above), a split hose somewhere or the intercooler pipe being loose.

Which Tyres
This depends on what you are doing, and your driving style. Eagle F1 tyres are some of the better ones but due to the soft compound, they wear easily.

Car overheating
If you car's temperature sensor has gone up to 130c, and your engine has told you to stop and check the coolant, it will most likely be caused by the water pump being broken

Engine Codes
A list of engine codes with specs can be found here: http://uk-mkivs.net/forums/thread/786306.aspx

My car is really bumpy and noisy when driving over bumps
This is normally caused by the suspension bushes being worn. Please see this thread about the bushes: http://uk-mkivs.net/forums/thread/1096565.aspx

Wheel Offsets explained
http://uk-mkivs.net/forums/thread/1096438.aspx

Details about Air conditioning system
http://uk-mkivs.net/forums/thread/1096434.aspx

Details about brake disks and pads etc
http://uk-mkivs.net/forums/thread/1096429.aspx

Details about speedo clusters and swapping them etc.
http://uk-mkivs.net/forums/thread/1096416.aspx

What should be average MPG be?
For details on approximate fuel figures, see this thread: http://uk-mkivs.net/forums/thread/1097857.aspx

Where can I find good Ebay items/Where should I put good Ebay finds?
There is an 'Ebay' thread here: http://uk-mkivs.net/forums/16/ShowForum.aspx

And some others: http://forums.vwvortex.com/zerothread?id=1835863

Where can I find a list of VAG-COM users?
A thread regarding the locations, and a link to a file in the download section can be found here: http://uk-mkivs.net/forums/thread/949849.aspx

Where can I find a list of paint codes?
You can get a list of paint codes with pics here: http://uk-mkivs.net/forums/post/224180.aspx

Where can I find a list of the fuse locations?
a list of the fuses with locations can be found here: http://uk-mkivs.net/forums/thread/1107014.aspx

Stereo Connector Pin Out:
http://uk-mkivs.net/forums/thread/1125935.aspx

Are Tuning Boxes any good?
See this thread for information about tuning boxes: http://uk-mkivs.net/forums/1153265/ShowThread.aspx#1153265

Short Codes –
MAF - Mass Air Flow sensor
VAG-COM - Diagnostic software for VAG cars. This can also be used for enabling/disabling additional features such as the alarm beep
VAG-Tacho - Is used for enabling always on needles, miles to empty and some other additional features

If you have some more FAQ's to add to this list, please post them in the FAQ Section here: http://uk-mkivs.net/forums/20857/ShowForum.aspx