A quid is a slang term for the British pound. So currently, 1000 quid (or 1000 pounds) is about $1500 US dollars.
Sidebar is a theme feature introduced with Version 2.2. It's basically a vertical column provided by a theme for displaying information other than the main content of the web page. Themes usually provide at least one sidebar at the left or right of the content.
In other words, your blog's sidebar is a great way to promote your content in a variety of ways and boost your online audience. Of course, as mentioned above, your sidebar is also a good place for advertising. Display ads, text link ads, and video ads can all be shown in your blog's sidebar. Remember, you can include your own videos in your sidebar, too.