The is a HUGE show, and well worth the time to attend. Unfortunately, I have a prior commitment and can't go this year (it will be my first miss in 10 years).
1) Prepare to do a lot of walking, especially if you arrive later in the morning. There is lots of parking, but it can be a hike to the show buildings. And you have about 10 acres of exhibits to cover.
2) Bring a couple of reusable shopping bags to carry stuff. Not all vendors have bags.
3) As with any show, know what you're prepared to pay before you go in. I've seen "Show Specials" that were higher than MSRP.
4) The Better Living Center is the biggest venue, but don't overlook the other buildings. Some of the better vendors are in the Mallory, Stroh, and Young Buildings.
5) If you can avoid eating at the show, do so. It's incredibly expensive and not particularly good.
6) Signs will direct you to take State Rt 147 (Memorial Ave) through the heart of West Springfield. Instead, take SR 52 to Main Street, and turn onto Memorial Ave from the WEST. This will bypass most of the traffic.