Welcome from Montreal. Alloy2 gave you great tips. Another good tip is to search the archives here. Also, rule of thumb, if it is stick to a magnet, it contains iron and value is pennies per pound. If it is metal, it doesn't stick to a magnet and it is absolutely free of magnetic iron or contaminants, that's where it gets better. Get the most copper, brass, aluminum, stainless steel etc. you can. It pays way better than steel or tin. If you have access to more than one yard in your area, check out their prices first. Not all the yards pay the same and if you have e-waste, some buys it, some other don't. If you ship to boardsort.com or somebody else, you need to consider shipping as a cost factor, because not everything pays enough to be shipped at your cost and make profits. I admire your determination, scrapping is fun, but hard work.