You will need to send a Covering letter with any applications you make. It should be well-presented to impress the employer. For examples go to the leaflet, Covering Letter.
You can also write to firms that you want to work for even if they are not advertising for staff. Many jobs each year are filled as a result of a ‘speculative' application’. For examples of letters of application see the leaflet, Writing for a job or apprenticeship.
You could send your CV with a ‘spec letter’ to improve the chances of your CV being read.
You may need help if you have a criminal record and are applying for work. Many employers will still consider you if they don’t think your conviction is relevant or you can show that you have ‘learnt your lesson’ and you are not a risk. Applying for jobs in the right way will give you a better chance of getting a job. For further advice see the leaflet, Applying for work with a criminal record.