Step 3: Put the legs together
Lay out the wood on the floor (or table), and make the marks for cuts. Cut them (use a miter saw, much, much more accurate then by hand), be sure to choose the nicer side of the wood for the top* (if you're staining it, if painting, it doesn't matter).
I'm doubling up the wood so that it looks better, that requires lots of cuts, and screws. Pre-drill the holes, and counter-sink the screws so that you don't see them.