I bought me a new 18" Stihl 250 the other day and am wanting to learn how to sharpen the chain correctly when needed. I talked to the guy from where I bought it and he told me in all honesty that I would be better off taking it to the chainsaw shop down the road if I wanted it done correctly. That doesn't sound like a plausible plan since they are going to charge around six bucks to do it each time and I can buy a new chain for thirteen dollars. I want to learn to do it myself. I've seen the sharpening guiders and was curious if they were any good or if I would be better off trying to learn to do it with just the file alone? To sum it up, what's my best route to to this on my own and not get the chain all out of wack.