Clear appropriate signage is essential. Consider working with a signage company to get a consistent professional look. Be careful not to break the bank and order only signage that you need and that can be used again if necessary.
There are likely numerous signage companies in your area so shop around to get the best price. Attached are some key areas you'll need signage for.
If you are selling tickets to your event an excellent website to check out is Eventbrite. Eventbrite allows you to create an event webpage, promote your event, and sell tickets through their website. It is free for non-ticketed events, and only charges a small service fee for ticketed events. Check them out.