How to send press releases

I have noticed that you can get a lot of attention (and free marketing) by sending press releases about your business. I get a lot of press releases every day from various sources and I see daily that regular people are using it for promotion of their MLM company or some services they offer. I am not going to tell you how to write a good press release, because I have never actually done it myself. I am will write a press release soon (about a new site I am about to launch). So, because of the press release that I am going to send out in a few weeks, I started to find a way to send it. It seems that there are many different services that will help you submit your press release. Some costs a lot of money, found some that would have cost me apx. $400, but I found one that seems to be very professional and it was free. At the moment I will use PRWeb to submit my press release. Their website is located at http://www.prweb.com