I usually will submit to only a couple directories a week. I know i'm supposed to submit to a lot of them, but I just don't have the time anymore. Yugo,
50 - 100 submission in free directories is safe as mostly free directory approval is a little bit slow.
i submit to as many as i can in a day. but i have a question, if i take out the reciprocal link in my page, will my page rank go down?
As many quality directories as you can, remember your submissions won't be reviewed instantly unless there are a number of editors for a particular directory sitting around twiddling their thumbs. People will argue building too many links too quickly will hurt your site but when it comes to directory submission for link building think about this, over a month how many directory submissions have you made? Of those how many will have been reviewed? How many will have been accepted and thus qualify as a backlink to your site and how many will be rejected?
banless is correct that some dir owners will review it when they are online, others will let it sit for weeks.
No matter with numbers (1,2,5,10,50) but they needs to be quality one to give you good link in return. DON.