To the best of my knowledge, you can't do it yourself. To get an item on there, it must be emailed to Art or Jan, unless it is something they have found to put on there. So if you have something you want on there, take the photos & write up whatever you want to say of it & email it to them.
From what I have experienced, it could be up quickly or sometimes later on, seems to depend on the volume of things they have to put there, and also I think they like to keep a good variety as to keep it fresh & inspiring & cover all areas. I think it is an Awesome blog & look forward to looking at it several times a day.