thumbnails

[Walalayo]

have no idea how to deal with thumbnails.. i have seen a lot of tutorials but is like none of them make sense at all..is there any place where i can find a nice detialed tutorial on how to make thumbnails of pictures that are already in a directory..or when they are been uploaded to the site.. and how to out put them becuase i t ried to use the code in the same page and it show all the page source code..