This thread have really good infomation... for drive traffic on site.. but some more techniqes which you can use for drive traffic...
forum posting
link building
directory sumbission
social bookmarking
press realease
article sumbission...

Dofollow is a tag. if your links added in dofollow than google will crawl your link and pass link juice to your site.. but if your link added in nofollow than google just simply coma on your link and go.. google dont give weigtage to your link...