There are ALOT of ways to advertise your site for no money. Only thing is, it takes time.
The best way I have found lately is Myspace.
I would first recomend getting yourself a myspace account.
Create your profile and add VALUABLE content. Something people will actually enjoy seeing.
Then also mention your business in your myspace.
They key is!
Find people on myspace who will most likely want to see your business and become friends with them.
To do this, you must first use your marketing brain and come up with some keywords you think your customer would put on their myspace.
Then, instead of using the built in "browse feature" that myspace uses goto google.
Type in this: site:myspace.com "keywords you came up with"
The result will be a list of profiles targeted via your keywords.
I hope this helps.