I need help with Bukkit

Hi, I just recently got minecraft server and I would like to have plugins running so I can have some things working, I have downloaded the most recent Dev build and I tried to run the .jar for bukkit but it did nothing I went into multiplayer and it showed the server was up but it would not let me log in so I deleted the Bukkit.jar, I don't know what to do, please help I am on a Mac Book Air if you would like to know, if somebody could help that would be great!