These three websites are really good for Pr submission: http://www.pressbox.co.uk http://www.forpressrelease.com/ http://www.onlineprnews.com
There are a number of press release site and i am sure you can Google it out .... anyways i'll do that for you . here have a look at this "avangate.com/avangate-resources/article/press-release-distribution.htm"
http://www.avangate.com/avangate-resources/article/press-release-distribution.htm http://www.talkandtalkers.us/free-press-release-sites-list-high-page-rank/90 Use these free high pr site lists....these are really good. Best of Luck!
There are many options available on the Internet but choosing the best one is tough job and time consuming for everyone. For making your task simple I will share with this list : http://www.directoriesdatabase.com/press-release.aspx. Hope it would be helpful for you.