so i got a background picture and cut it into slices. now the slices are of course different sizes.
on the free site how do i persuade bravenet that i want to put them on the page where i want - so to recreate the full image
Why would you want to persuade Bravenet to locate your images. Bravenet only provides web hosting and services. It doesn't provide web page coding support. Besides, it's your web page(s). You tell the images where they are suppose to go.
You could do it with a bunch of "div"s and use absolute positioning, but that's usually a poor idea on a free web site. The most common way to put image slices back together is with the use of a HTML table. There is lots of good information on the internet, so to avoid replication try this link to About.com - Why Slice?. It has a fair discussion on why you would even bother slicing a background image, and how to put the image back together. Some of the examples, however, are missing a few pieces.