Only submitting will be not good enough. After submitting your website just do a ping of the Social Bookmarking URL as well.
This is the Top 25 Websites as per PR, have a look –
Digg.com
propeller.com
reddit.com
claimid.com
folkd.com
Kaboodle.com
multiply.com
MyBlogLog.com
kwoff.com
gabbr.com
jamespot.com
linksilo.de
mobiseer.com
scoopit.co.nz
searchles.com
spotback.com
stumpedia.com
web2list.com
a1-webmarks.com
blogbookmark.com
blogengage.com
blurpalicious.com
bookfizz.com
buzzup.com
contentpop.com