I would print out maps of the fairgrounds before coming and drive around the grounds on Wednesday to familiarize yourself with the layout. Also figure up the absolute most money you are willing to spend at York, then double it, and take that amount in cash in a mixture of large bills and small bills. Bring two pair of comfortable shoes, a cheap poncho and some good sturdy shopping bags. Keep a small ice chest with some drinks iced down and a variety of snacks to keep you going until it closes. Make a list of what you want and research the prices using ebay COMPLETED sales with 2 or more bids. You can walk the entire show on Thursday but you can't do a lot of stopping and talking.
Relax and have a good time. You probably won't find everything you want, but you will see more "O" and "S" than you will see in a lifetime of those "other" train shows.
