How to print a full scaled image on photoshop cs5 on 8.5" by 11" paper?
What I mean by full scaled is, when it prints, it shouldn't have any white spaced border on the 8.5 inch by 11 inch paper.

Go into your printing options and decrease the border sizing. Should be at something like 1 1/2" inches or 2", put, TOP/BOTTOM/LEFT & RIGHT SIDE to 0".

That might work.