Optimize for search engines
While building the mailing list is a fantastic idea, It's kind of a different animal entirely.
Free adverting is also helpful, but often more time consuming than worth the return. You would be much better off doing link exchanges with other local businesses.
What I would do is make sure your website is ranking well with the search engines (Google, Yahoo, MSN). There are a tone of ways to do this, but starting off, I would make sure your site has pertinent information to what your potential customers would be looking for.
Take a minute to think about how your customers would google to find you and make sure you have those phrases in your website.
Also make sure your local information is posted prominently because most people are going to search for things like "house cleaning in Orlando" or "cleaning services Phoenix"
You can do a lot more in this area, but it's a good start.