Plea Definitions are provided here for your reference.
Guilty - You admit you committed the act(s) for which you were charged. You admit the act you committed is prohibited by law and you have no defense for your actions.
The State has the burden of proving its case against you. You have the right to hear the State's evidence and to require the prosecutor to prove his case. If the State does not, the law does not require you to testify or prove you were not guilty.
Nolo Contendere/No Contest - You are not admitting or denying you committed the act(s) for which you are charged. This type of plea simply means you do not wish to contest the State's charge against you. You may be found guilty by the Judge, but could still be eligible for deferred disposition or defensive driving.
Not Guilty - You deny you committed the act(s) for which you were charged. You have a defense for the offenses and will be set for pre-trial conference with the prosecutor and possibly a pre-trial date with the Judge to file any motions or subpoenas related to your case. After this hearing, a trial date will either be assigned at that time or sent to you via US mail. If you plead Not Guilty, the Judge may not hear ANY facts regarding your case prior to the actual trial date.