Before you start...
Buy a helmet. These prevent head injuries if you have an accident, and you should not cycle without one. Make sure it fits properly and has a recognized safety mark - ask in the bike shop

Be Seen!!!
By law you must have lights at the front and back, and a rear reflector to cycle at night, however this is only the minimum. There are also pedal reflectors, which are very noticeable, and reflective clothing is available, which is especially good is cycling at dusk.

Be Heard!!
Bells and horns are available, and many bikes may come with them already fitted. Let pedestrians, motorists and other cyclists hear you if you think they may not have seen you. Just because you are in a cycle lane, does not mean everyone will respect your right of way.

Road safety
Choose routes with cycle lanes and that avoid busy roads, though remember that other people may not always respect the rules of the road! STAY ALERT! Look after your bike to avoid danger to yourself and others. Check the tires and the tread and also moving parts often. Plus test the lights and brakes often.

Rules of the road
Follow the rules of the road - you cannot cycle through red lights, or down one way streets the wrong way - check in the Highway Code (cyclists section) for a summary of the rules. Young cyclists are often injured whilst attempting to do tricks and stunts - use your bike to ride not play!

Communicate!!!
Learn the hand signals needed to show other drivers your intentions - these are crucial at junctions and roundabouts. Put your safety first - if drivers make it unsafe for you to cross or join road, walk the bike to the nearest crossing point for pedestrians.

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Equally balance the weight of any items you are putting on your bike - investing in a saddlebag may be a good idea if you intend to carry items often. Remember to make sure that nothing can get caught in the chain or pedals, and keep your hands free!

A note about children
Rear seats and child seats are available - the maximum load for a rear seat is usually around 400 lbs (21 kg). A headrest is good to support the head of a sleeping child, and rigid, high impact, moulded plastic seats are usually best. Place any luggage in a front pannier, preferably a low riding one which will add stability.
The child will add quite a lot of weight, so check that your bike is suitable for the addition of a child seat - stability is crucial as is a low gear range for going up hills! Your local bike shop should be able to advise on the suitability of your bike.
Remember that the child won't be exercising, and will need to be warm and protected with its own helmet. Other than this - cycling with your child should be a fun shared experience, and will encourage a love of cycling in the child.