Early on you should have a logo that is versatile enough to use in different applications, such as print, web, embroidery on shirts, etc. You'll do best to have a version that can be converted to black & white without losing any necessary components. Some things just can't be seen in color (the easiest example is a fax transmission), so you'll want to make sure your logo won't be one big blob in instances like that.
Of course you're going to want business cards to pass along to potential customers, but don't forget about your workflow. Maybe you'll need carbon-less contracts for on-the-fly quoting, or letterhead and post/greeting cards to communicate with your customer. There's checks and deposit-only stamps to consider for your accounting department. And finally, you'll need marketing materials to sell your products or services. Brochures, door hangers, and rack cards are all good starts to creating a marketing campaign to spread the word about your business.
Your online presence is also important. According BigCommerce.com, 51% of Americans prefer to shop online. I'm not saying there isn't a need for brick and mortar, I'm just saying that there's a lot of traffic on the web that you don't want to miss out on. (Read full article here)
Whether you need a large outdoor sign for your business location, plastic / metal letters to affix to a wall, banners to announce the latest sale on products, yard signs to place in the yards of homes that you've performed services at, aluminum signs to direct traffic in your parking lot, vinyl to apply to doors and windows, magnets for your vehicles, well... You get the point. In fact, there's many uses for signage that it's impossible to list them all. Whatever the need, we have you covered.
This is the fun stuff! There are a million products that you can use to spread the word about your business, including travel mugs, t-shirts, pens, calendars, golf towels / balls / tees, and more, all with your custom logo. Not to mention the collared shirts with your logo embroidered on them for your employees to wear. There's even food gift items that you can deliver to your customers for the holidays. The possibilities are endless.
Over the years, I've come to realize that these are the three crucial steps that all companies must take to have a successful business. Organization, branding, and consistency are the body-language of your business. They're going to speak volumes to your customer without you EVEN SAYING A WORD. This includes the way you present yourself to the public from advertising, quoting the job, the workflow, and to the follow-up long after the job is complete. This is what separates you from everyone else.