For your first question
First go to "Settings -> Discussions"
Next go to the section "Before a comment appears" and uncheck both the boxes.
Note that by default a comment can appear without being in the moderation queue if at least one comment of that particular commenter has been already approved by an administrator. This is a very recommended setting. So please consider this before unchecking this.
On the other hand the other check box tells that who ever the commenter is, a comment from any person requires approval from an administrator.
For your second question
Go to "Appearence -> Widgets" then from the available widgets bar select a "Text" widget and pull it in your sidebar widget area place (primary area, footer, or where ever you want it to appear). Then fill up the text widget with a header and whatever text, including any links.