Multiple comparison

I have some question: :confused:

1. The formula to find the value of Tukey's Table
2. Std Eror, Sig, and Confidence Interval in LSD n Tukey HSD (in SPSS output), where it come from? (I mean the formula to find the value)
3. Which is better LSD, Tukey HSD, or Duncan ? And Why?

Sorry my english is not good...:D