Look at acas website - tons of information.
But first you need to establish basic procedures: plan of recruitment, record of recruitment, induction, training, contract, employee handbook, health and safety paperwork ie equipment training record,cosh etc.
During trial period you have a right to dismiss an employee if he/she turns out to be unsuitable. However be aware that you need to follow procedures(appraisals, training, progress report, re-training, employee work record.