You need to stop moving files and uploading things and look at your web page code. The fact that we can see the images for your tutorial links, means that they are uploaded and in the right place. If I use my right mouse button, I can easily see the full sized image behind it. But the page that the link go to has the images specified incorrectly. Below is an example from your "Tutorial 1.htm" page.

Note that the highlighted section references the C: drive on your PC. When you are viewing your page from your PC, that is a valid reference. But no one else can see your PC, so the image doesn't show. The image tag needs to read like the following, which specifies where the image actually exists on your web site.

You might think about making one of your tutorials on optimizing images for web sites. Right now your making the page use full size images and them resizing them in the tag. This makes the visitors browser download the entire image, and then resizes it locally. This wastes a lot of your bandwidth and makes the users browser do a lot of work. In order to make things work quicker, browser resizing is very crude, but even then, on slower internet connections, your site takes a long time to load.

You shouldn't leave the image quality up to the visitors browser. One of your image editors should give you the ability to resample the images, rather than use a resizing. Resampling gives you a much cleaner image than a crude resize can and you can link to the full size image, giving the visitor the option of viewing it full size. This will greatly reduce your bandwidth usage. If you need a graphic editor that has a very good resampling capability, download this one from IrfanView.com. It also has the ability to create thumbnail images and image galleries.

Bravenet meters bandwidth continuously and all uploading and downloading subtracts from your allocation. Their old method was to allocate bandwidth on a daily basis. So if you exceeded your allocation, you were only shut down for a day. They now allocate on a monthly basis, so if you use up your allocation in the middle of the month, you will be off-line until the first of the month. If you don't fix it now, it will be too late when it happens.