Oops, sorry I didn't understand that the first time around
Are you trying to add it to your album here on VAF? That should be pretty straightforward and each picture can be quite big at just under 100KB per image. You'll want to make sure you have the right file type and use GIF or JPEG only (is it possible the file extension your designer sent you is a PNG or TIFF?)
When you go into your VAF profile there is an option on the right hand side to create an album. Give the album a name, click the 'Upload pictures' link in the bottom right and use the image uploader to select and add images.
Once you've got the images uploaded you can grab the URL and insert that into your post using the image option in the text editor --->

<--- and it should display correctly in your post.
I hope that helps! If all else fails, Janine's suggestion to upload to a site like Photobucket is a good option too.