quicksand.js is a plugin, as such you should not modify this file unless you know exactly what you are doing.
#content is an example of an element to which you want to apply quicksand. You, not me, know what element you want to apply quicksand to. So you should replace "#content" by the relevant selector.
You put this code inside something like $(document).ready ( function () { /* In here */ } ) so that it runs at startup.
A call to the quicksand plugin takes 3 parameters I think. $(yourselector).quicksand ( a, b, c ).
"c" is a callback, i.e. a function that will be run when quicksand has finished quicksanding.
So it is inside this "c function" that you want to define the tooltip part.
And to apply the tooltip to an element, you do something similar to what you can find here:
You will notice that it is a long script, that you have to copy in full. But you will have to make sure that the selector, once again correctly references the elements to which you want to apply the tooltip.
Moreover, in my code example, I wrote "..." to say that the code is longer than what I wrote.
"..." is not a piece of code.