My take longer than a month for anything to happen, may not happen at all. It is very hit and miss these days and there is no rhyme or reason that I can see.
Make sure your mixing up your anchor texts real good use lots of variations. The web 2.0 SENuke type links almost do nothing these days. Try using some some blog comments and some blog posts combo lightly and mixing up the anchors, recently had and some luck with this.
In content blog posts and homepage back links are the two most effective links you can get, the higher PR the better. You might even try through in some bookmarks some cases they help.