These are not optional.
The law requires a helmet to be worn and fastened when riding a bike.
What kind of helmet?
The choice is vast. The best recommendation is to get yourself down an outlet that allows you to try a few on. From there you can work out what fits best and what style you prefer.
Can I buy a second hand helmet?
The choice is yours. But, it is impossible to be certain what has happened to the helmet in the past. Is it going to do the job when you need it?
How do I know if it is suitable?
Look for helmets that are marked up with an EC rating.
Is a visor essential?
A visor or goggles certainly help bugs and grit penetrating your eyes, which at best is uncomfortable.
Make sure that anything you select is appropriately marked and that it will not shatter on impact.
Can I ride with a tinted visor?
Tinted visors must let at least 50% of visible light through. It is likely to be marked as ‘not for road use’ if it is too dark. Tinted visors are not appropriate for riding in the hours of darkness.
Take a look at the SHARP website - Safety Helmet Assessment and Rating Programme, to help you make a more informed choice when choosing a helmet.