In the USA criminal offences are categorised as misdemeanours, violations and felonies. 'Getting done' (to use a lovely English colloquialism!) for any of them creates a conviction. So you have a conviction for a violation.
If the form asks if you've ever been arrested then (assuming an arrest preceded the conviction), you must answer 'Yes'. If it asks if you've ever been convicted of an offence, you must also answer 'Yes'. However if you're only asked whether you've ever been convicted of an offence of moral turpitude, you can lawfully answer 'No' (assuming, of course, that you don't have any other relevant convictions):
http://www.state.gov/...rganization/86942.pdf
Because your conviction does not come under 'moral turpitude' there is not an automatic ban on you being given a visa. It will be a discretionary decision; the only way to get a definite answer is to submit your application. (NB: Do so as early as possible. There have been reports, here on AB, for people having to wait up to 15 months for a visa decision).
Chris