Best of luck.

http://www.gatewaybizdev.com/blog/
References :
http://www.gatewaybizdev.com/blog/

Here are a few links that should help:
http://www.businessknowhow.com/marketing/24waysto.htm
http://www.sitepoint.com/article/business-8-steps-success/

good luck!
References :
http://www.businessknowhow.com/marketing/24waysto.htm
http://www.sitepoint.com/article/business-8-steps-success/

1. Search the internet for events in your area that have already passed and see if they display information about who advertised or sponsored their event.

2. Start cold calling local businesses. When doing this cold calls make sure you have information that the business is more than likely going to want. Such as how many people are expected to attend the event, what other businesses will be advertising there, and if any of their major competitors have already signed on to advertise there.

3. Emailing businesses can be effective but will be just as timing consuming as cold calling, and depending on your time frame to gather these leads, you may be better off making a call back list and just forgetting email all together because not all business owners or PR reps will respond in time.

4. Create a website for the event and have a contact form on the site letting people know that spots for advertising are open at the event.

5. Purchase a list from a reputable company that has done market research in your area of companies that are looking for events to advertise at.
References :
http://ezinearticles.com/?Forming-Strategic-Alliances-to-Boost-Your-Business!&id=2676856
http://www.cunninglyclevermarketing.com