Age for Training Maltese Puppies

Question
I have a 10 week old Maltese Puppy who is very smart already.  He comes when called, can go up and down the stairs, responds to "No-No" and has done extremely well with being alone during the day, barking, and just being a puppy.  I am trying to housebreak him (Hunter).  I am not sure he understands yet on what to do.  Can you please tell me at what age training should begin?  In fact, training in general with simple commands such as sit, stay, down, etc.?  I just love my 13 yr. old yorkie (Elvis)so it has been a very long time since I have trained a puppy.  Any advise you could give would be most appreciated.

Answer
ok house breaking should have started already but its ok some of my previous answers will help you with this, my first ever answers regarding puppy pads etc.
Maltese are very clever and they pick up things pretty quick. But what you have to understand is that they thrive on praise , they just love it, i taugh my pup to roll over by rolling him over and saying constantly roll over and getting excited lol shoutin yeah and eventually he picked it up, so for sit first sit him down state sit sit sit, and then yeah good boy lol then keep putting him in that position and saying the command, treats can help prectise more often, maltese love to please their owners it sounds "different" this technique lol but it works and make sure you teach them no treats for free lol they must do a trick or command first lol
Good luck !