Clone your blog settings to all new blogs youre adding. Copy settings like Posts, Pages, Theme settings, Blog options ...
Just create a blog which you want to use as default blog and set up the whole blog.
After setting up the default blog, go to the "Default Blog" plugin in the "Super Admin" panel and set up the "Default Blog".
When done, you will be able to select the settings you'd like to have in every new blog.
Every time a blog is created, the settings will be copied from the default blog to the new blog.
Thats it! Have fun.