"Beautify" function to align all notes on the grid

I write mostly dance music myself and like josh said there are a few ways to go about this.  You can use input quantize which is the easiest.  highlight your midi track, hit I which will bring up the inspector.  from there you will see all the options for setting it up...  You can also highlight the clip after recording - hit Q - to bring up quantize menu.

I totally agree with josh though about the quantizing sounding to robotic and sucking the goove right out of a performance even in dance music.  My two suggestions for this are when input quantizing.  On the drop down menu where you select value(1/4,1/2,etc) choose quantize settings- put in the value you want quantize to, uncheck the duration box, and then set the quantize strength to around 90%.  This will tighten everything up but will not sound as robotic.  Mess around with the strength setting till you get the results your after.  I also go in and manually change the note lengths in the piano roll view which can help funk things up a little.  You can use these same techniques when you quantize after recording also.

Hope that helps!