There are many forms of advertising. Word of mouth is by far the best.
Word of mouth comes from satisfied customers. There is no more solid marketing campaign than that, and it happens without spending a dime on advertising, if your product/service is good, and your customer are satisfied with the level of support you provide them.
Start locally, in the yellow pages, newspapers, local trade magazines, etc.
In fact, in the back of a lot of school yearbooks, the school sells advertising spots.
Do a lot of meeting and greeting, etc.
Traditional advertising online, is falling a little from what it used to be. Consumers are a little more cautious about websites and services than they were in the days of the .com boom.
This is where word of mouth comes to mind. You'll need people to back your company's claim of outstanding service, and there is no one better to do that than a current satisfied customer. This builds your reputation into one that the people can trust when they see your name on a banner or ad at places such as HD, WHT, PingZine, etc.