Before you think about submitting your site to a search engine, you need to be prepared. Dont think that because you have your domain name registered and a under construction page up that you are ready.
Dont even think about submitting your site to a single search engine until you are ready to receive guests or visitors. The worst thing in the world (I think so anyway) is to follow a link to a website and only find a under construction message or a front page with lots of links with coming soon as a reward for my click.
Why did I come to your site? I want to either find out something interesting, look at something, download something or buy something not to be told to come back later when you are ready to tell the truth, I dont think I would bother coming back. Even when you tell me to come back because Ill remember and think been there before, it was a waste of time, full of coming soon stuff.
If you have a blog dont leave the messages saying Just testing or congratulations and welcome to your new blog. Dont even think about writing Welcome to my blog, over the next coming few days I will be Just remember, the internet has no concept of time, but...