First, learn about and decide what type of trade show display that you want buy.

There are at least three ways to learn about the types of trade show displays on the market today. You can visit your local dealer show room, you can read about them on the internet, and you can attend a trade show.

I recommend: Attend a trade show and walk the aisles looking at the various trade show displays. Nothing beats seeing actual displays in actual use to see what works (and what doesn't). Ask exhibitors about their trade show displays and what they like and/or don't like about them. Be brief - exhibitors are there to market their products and services, not to tell you about their displays. PS. Read the last Action Step below for the most important consideration for selecting the right trade show display.

Find and buy your next trade show display on the internet.

Buying on the internet gives you a much wider selection to choose from. It is much more convenient, and it will save you considerable money over buying at your local trade show display dealer.

I recommend: Search for "trade show displays" on Google. You can also try Yahoo or MSN, but I like the quality and relevance of Google's results when it comes to looking for products and services.

Evaluate the trade show display company.

You'll want to determine the quality of the company that you're ordering from. How long have they been in business? Do they have an toll-free 800 number? Do they provide complete information and pricing on their website, or do they just use their website as a billboard or yellow-pages advertisement, and expect you to call? Most importantly, does the company have a list of customer testimonials and reviews on their website?

I recommend: Buy from a company that's been around and will continue to be around, that provides complete information and pricing on their website, and that has excellent and extensive customer feedback and reviews.

Evaluate the trade show display.

There are several factors to consider (read the last Action Step below for the most important factor). Among the factors are: How portable is the display? Is it easy to set up (and re-pack)? How durable is the display, and what kind of warranty does it have? Some companies now offer lifetime warranties on their display frames.

I recommend: Buy a trade show display that has a lifetime frame warranty.

Evaluate the order shipping cost.

"Shipping and Handling" is a notorious hidden cost in internet buying (sometimes the shipping on a product is more than the product cost!). A select few trade show display companies now offer free ground shipping on their displays.

I recommend: Buy a trade show display that includes free ground shipping.

Evaluate the ordering process.

Surprising, not all websites that sell trade show displays offer on-line ordering. Some expect you to call and talk with a sales person. Of those websites that do offer on-line ordering, some expect you to register and create an account before you can order. Only a select few websites selling trade show displays on-line actually provide on-line ordering that is easy, fast, and registration-free.

I recommend: Buy from a company that provides easy, convenient, secure on-line ordering.

So WHICH trade show display should you buy on-line?

With all the different styles and types of trade show displays, which display should you buy?

I recommend: This question is really a subject for another guide, but I'll say this: Your trade show display is a business tool, plain and simple. The single most important thing is that it gets the job done. The primary, fundamental purpose of a trade show display is to differentiate your trade show booth from the several hundred other booths at the trade show. Your trade show display should stop qualified prospects as they walk by your booth. To accomplish this you need full-size, attention-grabbing graphics with a clear, focused message. Thus, the most important feature of your trade show display is that it should be completely covered with full-size graphics, and the graphic design must be effective. In a nutshell, a common "run-of-the-mill" trade show display with an compelling, effective graphic design will always beat a "top-of-the-line", fully-loaded-with-all-the-bells-and-whistles trade show display with a mediocre graphic design.
Once you have an effective, compelling, full-size graphic design, other considerations include: how portable is the trade show display (will it cost an arm and a leg to ship?), how easy and/or expensive will it be to update the graphics, is the display modular so that you can add to it as your company grows, does it have a rugged and durable design, and is it easy to set up (and to take down and get back in the shipping case).
But remember, the single most important thing in a trade show display is full-size color graphics and the graphic design you put on it.