1. You need a badge. Elaine Wright Colvin pointed out that your book publisher can provide a badge or if you hire a publicist, they can do that as well. Otherwise, you pay to get into the trade show. The cost varies from year to year so you can check their websites. The BEA's rates depend on your category (e.g., author, publisher, library).
Some trade shows and conferences arrange for a block of hotel rooms at a special price for that event and you can save money.
2. Go with an agenda. That is, know what you want to accomplish. Those four words helped me. Until Elaine personally walked the floor with me at a trade show, I didn't know what I was doing and felt overwhelmed by the displays and books for sale.
Elaine helped me to figure out what I wanted to do. And that year, I wanted to meet editors. With her help, I contacted about a dozen in advance of the show and set up appointments. On the floor, when Elaine saw an editor, she called out to them and introduced me.
In 2006, I wanted to meet publicists and made appointments with eight of them. I learned a great deal about what they did and compared their rates and services.
Another agenda might be to set up interviews. TV and radio studios record at trade shows. But always ask in advance, because by the time of the trade show, they're filled up. I suggest two months in advance.