If you see this post it means that BlogEngine.NET is running and the SQL Server provider is configured correctly.
If you are using the ASP.NET Membership provider, you are set to use existing users. If you are using the default BlogEngine.NET XML provider, find and open the users.xml file which is located in the App_Data folder. Edit the default user and provide your own name as the username and a password of your choice. Save the users.xml file with the new username and password and you are now able to log in and start writing posts.
Since you are using SQL to store your posts, most information is stored there. However, if you want to store attachments or images in the blog, you will want write permissions setup on the App_Data folder.
On the web
You can find BlogEngine.NET on the official website. Here you will find tutorials, documentation, tips and tricks and much more. The ongoing development of BlogEngine.NET can be followed at CodePlex where the daily builds will be published for anyone to download.
Good luck and happy writing.
The BlogEngine.NET team