Ideally how many to start?

[walrus]

It really depends. I don't even think with splogs as you can have pretty much however many posts you want when you load in the feeds.

With a hand written sales blog, I would say 10 to start submitting to directories and setting up link trades although I submit to technorati, feedburner, google and yahoo immediately after my first post.

If your doing something along the lines of a real blog, even if it's adult slanted, I start submitting to the more mainstream directories after about 7 posts. A few will reject you for not enough content but those I just submit to a couple months later.