Most factory hammers come with a flat face and a relatively sharp pein, but for forging a flat faced hammer is difficult to control and tends to leave an ugly finish due to the edges marring the work. A good forging hammer should have all the edges chamfered and rounded and the face should be crowned. I usually forge with mostly a heavily crowned hammer (or a rounding hammer) of around 2.5-3 lbs and use a lighter hammer with a slight crown to planish the surface smooth. The pein should have a gentle radius of perhaps 1cm or more to avoid putting difficult to remove divots in the work and the pein should also be slightly crowned across its width. Making hammers is not rocket science, but if you have never made one before it might be a little tougher than expected. The balance of a hammer depends on the preferences of the smith, but most people find that having the center of mass just toward the flat face to be the most comfortable, this makes striking with the flat face efficient and the pein side usable. Put the center of mass too much toward the flat face and the hammer feels unbalanced when trying to use the pein. Also, don't forget to make the eye in an hourglass shape otherwise it is pretty much impossible to keep the handle tight. If you plan on making multiple hammers the other type I recommend making is a rounding hammer, between a cross pein and a rounding hammer almost any type of work can be done. Most experienced smiths like hammers with a fairly hard face and pein, but it is safer on your teeth, your anvil, and other tools if your first hammers are a bit on the soft side (there are always a lot of missed strikes when you are first learning and a hard hammer on a hard anvil will rebound high enough to break your nose or knock teeth out of your head).

As for files, I don't have much in the way of good advice--------I buy used files almost exclusively and there used to be a lot of good brands available, not so much any more... If he will have a decent grinder then the files won't be relied upon as much. A bastard mill, mill, half round, chainsaw files (in a few sizes) and a decent set of needle files is a good start. I don't have any because they are too expensive, but I hear that the Grobet INOX line of files is about the best in the world. The other type of files that I highly recommend for knife makers is a flat and half round dreadnought file, these are great for shaping handle materials like wood, bone, brass, etc...

If you have any decent amount of S7 around I would use it to make all the hot work tools (chisels, punches, etc), something like H13 is obviously better, but the reasonably high chromium and molybdenum content of S7 makes it the next best thing to a proper hot working steel for blacksmith work.