A logo is a great way to create recognition for your trucking business. People quickly make associations between symbols and short phrases, whether that's your company name or a tag line or motto. Keep your logo simple and clean so that it's easy to read the text and see the graphic, and people will remember it.
Choose a color scheme. If the trucking business already has an established color scheme on its business cards or other materials, stick with those colors in order to create continuity. However, a logo tends to have more impact if it uses only two colors, so if the color scheme includes more than that, choose the two most dominant colors, or the most dominant color and one contrasting color, and use those for the logo.
Choose the main text. The dominant text of the logo should be simple, short and easy to read. It could be an abbreviation of the name of the trucking company or the first word in the company name. If the entire company name is short enough (two words), that could work as the main feature of the logo.
Choose a corresponding graphic. If you're handy with graphic design, you could create your own picture. If not, search for royalty-free photos or images or get permission to use a graphic from its creator. Pick a graphic with clean lines and not much detail. You want the graphic to be easily recognizable in a single glance. A line drawing of a truck, highway, wheel or some other related object works well.
Merge your text and your graphic. This is the trickiest part of the whole process and requires playing around with your text and graphic elements to see what works best. You could try laying your text over some portion of your graphic. If you use a picture of a truck, perhaps your text would fit on the side of the truck. Or you can fade the picture into the background and simply lay the text on top of it. If the graphic is small or flat, you might be able to divide the logo into sections, with text dominating in one section and the graphic filling up the rest of the logo.
Add a tag line. This is not necessary, but if you have a short, memorable tag line then play around with placing it somewhere on the perimeter of the logo. If it clutters up the design too much, skip it.