how much notice to give employer

Welcome to the site,

Let me answer this for you relatively simply:

A contract of employment is an agreement between employer and employee and is the basis of the employment relationship. A contract is made when an offer of employment is accepted. A number of rights and duties, enforceable through the courts, arise as soon as this happens.

Most employment contracts do not need to be in writing to be legally valid, but writing down the terms of the contract will cut down on disagreements later on. The Employment Rights Act 1996 requires employers to provide most employees with a written statement of the main terms within two calendar months of starting work. Many employers include an introduction to terms and conditions as part of the induction programme for new starters. This gives employees a chance to ask questions and for the employer to test understanding of the employment contract.
Taken from ACAS

The notice you should give your employer before resigning should be in the contract. If your contract does not say how much notice you must give your employer then, if you have worked for one month or more, the minimum notice you should give is one week. If you have worked for less than one month, the notice period should be reasonable. Although i would say one week is reasonable, giving them time to find an agency driver to cover or alter employees timetables to cover from when you leave their employment.

If your contract says you must give your employer more notice than this, you must give the amount of notice in your contract. Your contract may set out how much you must give, whether it must be written, and/or when you should give it.

If you leave your job without giving proper notice, your employer may try to withhold part or all of the money owed to you. In general, employers are not legally entitled to withhold money owed, unless your employment contract allows for it.

if they attempt to deduct monies from your earnings cause of improper notice you should seek legal advice, both of the two organisations listed below will give you free legal advice other the telephone:

http://www.acas.org.uk/index.aspx
http://www.citizensadvice.org.uk/

Hope this helps