For question 3, images in sidebars, there are a number of ways, most involve uploading the image first via the media panel.
You can then add a text widget and place a bit of HTML code to display the image. A simple image link would look like this:
Code which adds a link to an image, etc. is:
Or you could use a widget that works out the HTML for you, Simple Image Widget is one that springs to mind
<a title="Image Title" href="http://www.yourlinktarget.com"><src="http://www.yourdomain.com/yourimagename.jpg"></a>