Plane basics - Bevel up or down on #4, #5 and #7 planes

Generally speaking, all standard handplanes are designed to work with the bevel down, thus allowing the chipbreaker (the curved plate with the big flat screw) to be positioned close to the cutting edge for maximum support and chipbreaking action.  Planes designed for bevel up use generally to not have a chipbreaker and instead have a much thicker blade; they also have a lower blade angle since it's the degree of bevel that establishes the true cutting angle.  Most standard planes have cutting angles around 45 degrees.  More advanced planes, like infill smoothers and lie nielsen types may offer higher cutting angles, but you can simulate the effect by adding a back-bevel to your blade.  The advantage of a higher cutting angle is less tearout on highly figured woods, but 45 degrees is adequate for most planing tasks as long as you learn to read grain direction and go the right way. 

Something else you should realize if you're new to planes, is that you will have a pretty much miserable experience with them until you learn to sharpen the blade to a razor's edge and fine tune all the adjustments.  Once you get this mastered they are a real joy to use.  My first handplane was a plastic handled monstrosity from a pawn shop that destroyed its test board.  I almost swore off handtools until I happened across a vintage stanley from around 1900.  After a careful restoration and the improvement of my sharpening technique I was taking off whisper thin shavings with no tearout.  I've never looked back!