recently minecraft just updated from 1.4.2 to 1.4.4. i do not know how to update the bukkit server . please help me
There's no Recommended Build for 1.4.4, yet. All you can do is get the latest dev build, and replace your old craftbukkit.jar (or whatever you named it) with the dev build jar. Needless to say, backup your worlds first, and be aware that some plugins will require to be updated as well. If you don't even know how to update your bukkit server, it may not be the wisest idea to use development builds, though.
Just wait till a beta or stable release comes out, I never touch dev builds, unless I'm using my localhost :3