I'm sure you have a marketing department so i won't repeat marketing 101 here, but if I were to look at this from an outsiders point of view, which I've never worked in this industry before, I'd say your biggest challenge is building up trust with your potential customers. If I'm shipping product I would imagine it's important that it's on time, and that it's also important that it gets there safely, so even if you were to offer me a great deal, I might be hesitant to go with you since you're a new company.
to get around this I would do two things right off the bat. First, I would make sure that any type of marketing I approached potential customers with emphasized the owners and managers, their back grounds in this industry as well as how to reach them quickly and conveniently. I would put this information on your website, in your brochures, at the bottom of your letter head, basically everywhere in order to let you potential customers know that you're not just making empty promises when you tell them they mean everything to your business. Back it up with proof, give out owners and managers cell phone #'s so they can be reached at all times. I know, sounds a bit extreme, but as you already know, starting a business is a bit extreme too.
The second thing I would do in order to build trust with potential customers is I would consistently approach them to use you as an emergency back up choice in case the shippers they work with regularly can't help them in a jam. edit