Here are some tips to taking a good screenie:
To create a screenshot, press the Print Screen (Prnt Scrn) button on your computer - if you're on a laptop, you may have to press your Fn button first.
Open up your paint program and paste the picture. Crop the picture so only the important stuff is showing.
Save the picture as a .png or .jpg. Jpeg is prefered, for it creates a MUCH smaller file. If you use a program like PSP or GIMP, you can save your picture as a .jpg and it will still have very good quality.
GIMP is a small, free program. It's like a basic version of PSP. I recommend getting it.
You can upload your pictures to sites like
Photobucket or
Imageshack