Well, what's your budget? There are many ways, but the cheapest and easiest is simply post it on Craig's list. You can design a nice flyer and save it as a pdf and post that as the ad. There's a way it comes up as the whole page. Not sure exactly how to do it but if you google how to post a full page ad on craig's list, it should come up with instructions.
Another inexpensive way to recruit is to put ads in newsletters like church's, schools, club's etc. Also, ask if any retailers or restaurants will let you post flyers in their windows. Post flyers with tear off numbers in store buletin boards.
But, if you have a budget, I would suggest a website, facebook and twitter. This gives you a venue to do trade banner ads. You can choose who can post on your site and pages and who you want to show your ad. This way it's mutually beneficial and you can reach the right people. For instance, dance apparel shop would probably happy to do a cross web banner trade.
Plus, you can follow twitter and facebook pages where you think you will find your target audience and "Like" them, make comments, etc. to drive people to your pages and site ultimately calling you to get classes.
Report Andrea's answer
Along with building out an advertising budget, another necessity would be a marketing strategy. The core of this should be identifying the customers you are targeting. For instance, when I was starting my dance studio in a college town, I decided my target audience would be non-students with mid-level incomes who were interested in fitness and artistic expression. This led me to specific radio outlets, regional magazines, and targeted Facebook advertising.
Report Scott's answer
Startups in your venue usually benefit from a basic web site (a Word Press or Google Blog is free, as are many of the social media sites that can be linked to it. The process requires a front-end loaded investment in time, but it is well worth the effort when using free or very low cost utilities on the Internet. The return may surprise you. A blog is quite different from a web site. Provide good, solid information free of charge and use blog searches for synergistic businesses to team with. Teaming is an absolute necessity these days. Be prepared to provide information, samples and valuable service gratis as a marketing tool. Introduce yourself and then immediately engage the client or potential teaming partner with your presentation tools available to bring your expertise to whatever topic they are interested in. Let them take you where they want to go with their concerns and their needs. Apply your presentation tools and expertise dynamically The idea is to refer clients to article links at your web site and your blog to avoid having to repeat yourself over and over in new business marketing, thereby keeping yourself available for specific inquiries and closing deals. Link everything together and begin answering questions as well as registering at many of the free applications for networking web sites on the Internet to see how that can benefit your product and services. Utilities like Twitter, Facebook, Empire Avenue, Pinterest and About Me will serve your site well. You may wish to consider Google Ad Sense for cash flow. It is free and could supplement your income with ads in the margin of your blog. Integrating and networking platforms together is the best approach. Most of the free applications of the type discussed here have profile features to link back to your blog and many will automatically publish your content on their site, once linked. Content is king and the queen is a hub of strong useful information with spokes emanating from it like those of a wheel to many free social networking platforms where your brand, your consistency and your offerings drive the engine that is your enterprise. * http://www.smalltofeds.com/2015/05/why-social-network-to-promote-your.html ***