BrowserCap
Allows you to capture the screen you are currently working on. Also allows users to print the Internet Explorer or Mozilla Firefox webpage as you see it, and not in a printer friendly view. Limited but can be handy.

Cropper
This is a very basic screen capture tool. Would recommend others above this one if you are after simplicity and other features.

King Kong Capture
Great tool. One of the best free options available. Has many different options for capturing images including rectangle, free hand or whole browser page.

Screen Hunter
Very simple and basic to use. Either save your cropped images directly to a selected destination or to your computer's clipboard.

Super Screen Capture
Great free software that gives you a 7 day trial of their pay products. Free version offers 3 simple screen capture features that are very user friendly for even the beginners.