Enco is rather skimpy on information, but the tool steel from McMaster-Carr comes annealed so that step can be skipped before working it. If you did need to anneal it, you would heat it to bright red or orange and use the magnet test that Matt mentions in his link. When the steel is annealed, it needs to be cooled very slowly. Something like the brick furnace might work well for that.
After working the tool to shape, it is heated again to the same color temperature and held there for a couple minutes for a small rod. Next, it is quenched in oil -- stirring quickly to get fast cooling. I don't know about using mineral oil for quenching -- I would be concerned about it catching fire because of its relatively low flash point. There are some vegetable oils that have a very high smoke point. The person who showed me how to make hook tools used extra light olive oil for quenching. I had not thought about a toaster oven for tempering after hardening by quenching in oil, but if the tool fits inside, I suppose it could work. I just used the kitchen oven at around 425° F for about 30 minutes. What you are looking for is a straw colored oxidation. A tempil stick is more precise, but judging by color is probably more than good enough.