When it comes to buying lumber, all you need to know is how much you need. Stay away from the imported crap that HD and lowes sells, its too exspensive anyway. I go to my local building supply place that local contractors use......often you can even get the contractor price if you produce a business card. You can pretty much forget about picking through it to find the good stuff with tight knots, most places will not let you because it leaves them with a mess. lumber comes in grades of Premium, #1 and #2 select. Pretty much if you want tight knots or no knots you have to buy the expensive stuff, otherwise you get knots and cracks. I buy the cheapest stuff available which is currently 1x8x16 SYP at 9.44 each.