Gypsy: First, look at the staistics column. The most frequnt letters are "e" and "t" in most cryptograms. Watch for words like "experience" and "little" and "success." If the cryptogram is a quotation, think about the person being quoted, and ask yourself what that person would be likely to say. A quote from Shakespeare would have different words in it from a quote from a modern politician or sports figure.
Flutefish says look for word patterns to solve ciphers like short words with double letters in the middle - you know if a 4 letter word has double letters in the middle, the middle letters are prob 'o' or 'e; I also look for 'the', 'that, etc - really common words that can help me get started
Gypsy: words ending with s single letter followed by double letters usually end in "ess," but if the cryptogram a quote from a sports figure, they're likely to be "all."
this is a pretty good website for beginners