I have heard that socialbookmarking your site to different sites improves ranking and overall performance. but also heard that most of the sites use NOFOLLOW. is it true that sites like digg uses nofollow. So how will they help in getting hign pr?
Well.. Digg is do-follow. Infact there are many social bookmarking sites which have do follow plug in installed. http://www.caroline-middlebrook.com/blog/do-follow-social-bookmarking-sites/ should provide you a good list of these sites. Besides, do follow is something that is taken into consideration by Google. No follow backlinks have the same importance as do follow for Yahoo searches.
There's no such thing as the "dofollow plugin". Dofollow is simply a link that doesn't have the nofollow attribute in the html A tag. You can download the Search Status plugin for firefox and select the "Highlight nofollow links" plugin...to have all nofollow links on a web page highlighted.
social bookmarking helps for sure. there are 100s of Sb sites and some are nofollow but there are plenty of SB sites that are dofollow as well. i however suggest you to submit slowly. submitting to lot of them at once and not submitting to any later on will not help much in the long run. keep submitting slowly.
social bookmarking really helps in terms of traffic. some SB sites uses dofollow so it can really be helpful.
It does in terms of SE ranking. My affy site book marked on Propeller comes out #2 on one of my long tail keywords...Madonna tickets Los Angeles The results chop and change daily, and I keep social bookmarking daily, but the SB helps me be competitive against some really big sellers in my niche. (somewhat competitive