When you say “I am assuming hooking up with caterers and maybe even schools”, does that mean these are the two categories you’ve identified as your target market? You might consider other options as well, such as event planners (or planning companies) and venues (e.g., hotels, event halls, etc.). Typically, venues and planners have preferred vendor lists. If you can get your name on several of those lists, your company will be exposed to a wide variety of potential clients and potential repeat business. Also, consider going directly to the source by advertising online on B2C vendor sites in your local area.
What is your web presence like? If clients are searching for you independent of an event planner, they’re probably going to go online. If that’s the case, you need to build your credibility on the web with the basics: strong website presence as well as a presence social networking sites, strong presence in the online event community for your local area and social media presence, such as Facebook (and other industry related sites).
For your website, be sure to promote your services by giving customers a “taste” of what you offer. If a potential customer is going directly to your site to see who you are, show them the products and the services with pictures, videos of your fountains (or yourself, demonstrating the fountains) or testimonials from customers. Let them know why you're the best choice in the market for a chocolate fountain rental.
Also, (if it is cost effective for you) consider marketing your services at events like wedding conventions or similar events. That way, people can get a taste of your services in person.
Best of luck!