When designing something new it is important to consider what message you're conveying with the choice of colour scheme. Find out more about the meanings of a variety of different colours here
If you are confused by all of the different graphics file formats and when to use them, then check out the information here.
Interested in Adobe Software?
There is plenty of useful stuff here for Adobe Photoshop, Illustrator and InDesign, including, information about what they can be used for, together with links to a number of tutorials. Need some inspiration, or general help with graphic design? If so, there are a number of links to useful resources here.