Even though guidelines are not published, the program starts from the date it is announced. All you need to do is creating a good blog on blognagar(No copycats are allowed :) , you need to write your own content).
Once the guidelines are published (mostly they are for winner deciding procedure) you can submit the blog as per instructions published soon.
Ofcourse you can submit more than one blog as well. (Please note that a blog does not mean an article rather a blog address. You can create as many blogs as you want on blognagar.com. Each blog may contain any number of posts)
When opportunity is in front of you, don't hesitate to catch it. It will never come to you again. - Maverick