Hi,
I have just joined this site, so I am a bit late!
the simple way to add a front cover to an epub book is in itunes
I use my computer to drag the ebook from MS Explorer and drop it into iTunes. (I'm using a Microsoft computer)
In iTune search by author or name
Then highlight it and right click with the mouse
On the dropdown menu click on "Get inf"
this will show you the info on the book you have added
Go to "Artwork", in there it lets you browse to Microsoft Explorer
You can use a picture (jpg extention) for you front cover.
I usually go to fantastic fiction on the net to get a front cover
if you search for the book, you can usually find it.
Below is the link for Fantastic Fiction
http://www.fantasticfiction.co.uk/
It will show you the book in question with a small button picture, however, if click on the book you want, you will be prestented with the full size Picture to use as a book cover.
Right click on the picture, then you can "save as" to your picture folder on your computer
Once the picture is in your folder, (I usually change the jumble of numbers they give, and give it a proper name) do like I said at the top of this example - browse from the "Artwork", click on add to bring the picture into the books info file.
then OK to update the file.
Now all you have to do is click sync in itunes to update your iPad.
I hope this helps, it is a bit long winded.
Yours MeerkatSqueak