Prepare to talk about your business specifically and in a way that non-professionals in your field of business can understand you.

 
Bring plenty of business cards, the more the better.

Dress to make a good impression but be comfortable.

After the event follow up and follow through.

Try to keep in touch or maybe even start a newsletter.

Keep the collected business cards and notes or even jot down the addresses and contact into your outlook system as you never know when they will come in handy again.

Its true, networking involves work, but with enthusiasm and a good preparation it can be fun and help to take you far in business.