You might want to inquire to the date in which your conviction is listed 'spent' Normally minor offences are wiped at 18. However I'm unsure about more serious offences.
At the end of the day its about context. If you can show by your conduct that it is in the past then this is favourable. Qualifications, Volunteer and paid work, good character and work references will work for you.
You may find however that with a crowded and competitive job market at the moment that your disclosure of a criminal conviction may see you set aside in the first vetting stage (eg, looking through CV's and decided whos worthy of an interview) Because of the volume of applications bigger employers have a habit of doing this. This you cannot help now, so concentrate on your skills and experience. Write in the criminal convictions section your offence and the context (eg: bad time in my life, insecure, etc if true) and how you have turned your life around.