Blog management is available in the Configure Blogilo dialog, and is accessible via the → menu, or alternatively via the → menu.

To add a blog, you simply have to insert your blog address, username and password in the corresponding fields and then click the button for the most popular blogging servers, such as Wordpress. It will guess your blog, and api, and then will fetch your Blog Id.
If it fails, you can manually select your blog's API type in the Advanced tab and click to fetch your Blog Id, or enter your Blog Id if you know it. And if you are using a “right to left” language, select Right To Left in next drop-down list.

You can check what Blogilo supports for your blog in the Supported Features tab.