Overview.html
When you click on a single mission, on the right, you see the overview, which is mostly comprised of a picture and one or two lines of text. Tutorials on how to make an overview can be found on OFPEC. Alternatively, you could un-PBO an existing mission and use its overview as a template.
Many people have trouble creating a good overview picture. Here is some support.
Pictures must be in the following sizes.
64x64
128x128
256x256
512x512
And so on. Note however that very large pictures will not fit on the page.
For an added touch of professionalism, centre your text by adding the following above your main body of description.
Version numbers and mission author details shouldn't really be put on the Overview scrren. Such information should be left in the ReadMe.