If you're still manually grabbing website screenshots, you're living in the past. Get Awesome Screenshot for Firefox and Google Chrome. Because it is what it says it is.
When you want to take a screenshot of the contents of a website, the standard computer screenshot tools are rarely the best solution. And we're almost never talking about a website that fits onto a single screen, right?
One great screenshot tool is called Awesome Screenshot and it is what it says on the box. Install the Add-on for Chrome or Firefox and you'll get a new icon on your toolbar. A click gives you the option of capturing the visible area, just a selected area of the window or capture the entire web page. Once captured you can even edit and annotate what you've captured from within the tool, then save the image anywhere you like or share it online immediately.
Great features that make a light work of a very useful task.