Entries from blogs are only cited as notes. But if information from a blog has been extensively used the blog may be included in the bibliography, too. For the citation that you require as mentioned in your query, the appropriate format of the citation is:
Artist’s last name, first name. Title of art work, medium, date of art work (Institution where art work is housed (if known), city where housed if already named). URL.
The URL should be of the form: Name of blog (blog), date and time it was accessed, URL of the blog
If the blog's name contains the word blog there is no requirement to write blog in parenthesis.
Assuming you have accessed the blog today the citation would be of the form:
Baker, Simon. Propeller Heads, medium, 2004, (Brussels International Airport terminal). Chad's Art 101 Blog: Creative Notebook, April 24, 2012 (11:46), http://chadvan.blogspot.in/2007/09/creative-notebook.html
Medium has been made bold as I do not know the medium, you are expected to have the required information and fill that in.