ruded

What is the best way to add iron sights? What is a cheap way to add iron sights? I have one of these, except it has a PRS rear butt stock. Rest is stock i believe. http://www.dpmsinc.com/firearms/firearm.aspx?id=53

Only really been shooting for about a year. Recently got a LR308L Have not shot it too much yet. I have lots of questions to ask. Look forward to all y'alls help. thanks