how do i add more alphas to my startup alphas palette. 
Go to here - http://www.pixologic.com/zbrush/downloadcenter/zplugins/
See the Alpha an Texture Loader (also all goodies are useful).
Go to here for learning material - http://www.pixologic.com/zclassroom/
Go to here for Wiki and Doc’s - http://www.pixologic.com/docs/index.php/Main_Page
Have fun with ZBrush 
small_orange_diamond