The basic 'tool and lubrication kit'
Metric 'spanners' - 8,9,10,11mm sizes of both the box-end and open-end types
A Socket set is very useful though not essential.
Screwdrivers - flat head and Phillips
Allen keys-the standard type are good but the long workshop type are much more useful
Pliers - these will be used for pulling cables.
Large adjustable wrench-This is for use on headsets and bottom brackets
Bike wash and wax
Oils and greases:
Light spray lube for cables
Teflon spray for all round use and summer riding
Adhesive oil for winter use
Selection of greases including waterproof and copper
Toothbrush - this is the easiest thing to use to degrease components
Tools that should never come close to your bike
Worn wrenches: they damage the nuts and bolts you use them on.
Self-locking pliers: they damage the nut or bolt you are trying to remove and the surfaces and paintwork in the area you are working
Hammers, however there is one exception. When altering the height of the handlebars, cushion the blow with a cloth or piece of wood.
Use a box-end spanner or a socket wrench whenever possible. An open-ended spanner is very likely to slip so avoid using one whenever possible. If you must use an open-ended spanner, steady your hand against other components to avoid stripping the head of bolt.
For most jobs you won't need a socket set, but if a bolt is hard to reach, it is an ideal tool so having a set is often well worthwhile.
Allen-head bolts tend to fill with dirt, so clean them before trying to make adjustments. Also, make sure that the Allen key goes all the way into the bolt before you try turning it.
If an Allen-head bolt is 'buried' in a component, try reaching it with the long leg of the Allen-key. For these jobs long workshop type Allen keys are a real benefit
You will find a Phillips screw on a derailleur and pedals. Make sure that your screwdriver fits all the way into the screw; otherwise it may get stripped.
When stripping components (for example a derailleur) lay the small parts out in order as you take them off and in the direction they were installed.
Anti-seize compound should always be used when bringing two different metals into contact with each other, for example when you put an alloy seat post into a steel frame.