If it says 1/2 step, the note you bend to would sound like the note in the next fret. If it says bend 1 whole step, the bent note would sound like the note that is two frets up. As for the 1/4 step, that note would be in between the note you're bending, and the next fret. That's pretty much the only way to put it, sorry if it sounds a little confusing.

You have to pull down on the 5th and 6th string when you bend them. They slip off of the fingerboard if you try to push them up.

When bending on the 1st, 2nd, you usually want to bend these by pushing them up. For the 3rd, or 4th sting, you can push them up, or pull them down.

Let me know if this helps, and if not we'll try to put it another way.

JD