The thing about Digikey is that you have too many choices for a beginner. Need a 10k potentiometer, you have 1500 choices. Sites like sparkfun give you a narrower selection which is actually useful. You don't have choice paralysis and you know you're getting something decent.
Check out http://www.taydaelectronics.com/
Sometimes cheaper than digikey or ebay. They also post coupons on facebook.