Go to the prosecutor after you've filed your not guilty option and ask for full disclosure. That means you request the cops' notes. they'll give you a photocopy of his notes within a few days or weeks following your written request.
Then after reading and understanding the police information, call around to several paralegals like x-copper, pointts etc. and ask pointed questions about what would be your best defense.
Armed with that information, you should be able to craft a solid defence.
If all else fails, if your hearing is delayed for several months, you can file a charter challenge (Charter of Rights and Freedoms) claiming your right to a speedy trial has been greatly delayed and requesting the charges be thrown out. That has worked for me.