There is more to studding then just having a well tempered male dog. You have to think of dirth defects or bad breeding. The best way to know your male is the best for studding is do you know his back ground do you have atleast a 5 to 6 year generation pedigree do you know the health testing that was done on his sire and dam and there sire and dam and so on and so on. Even a bad defect way back in the generation can come back and haunt you in an early litter. Its best to know all of this and have you male health tested as well..and there dam that he is bred to should also be health tested.
This is a good site to read on to know what some chihuahuas may carry and pass on to litters. http://www.geocities.com/Petsburgh/1495/disorders2.html
Another thing to read
Also more to consider...
I am sorry I do not mean to offend...I Just have been in chihuahuas for a long time and Have bred a litter myself I have 4 ladies that have been breeding for years and years one owns the top chihuahua in the United states that I follow and have been taught alot by them. Its best that you know what your getting into before you breed or stud. After all has been passed and your male has no health problems none were in his generation no birth defects or flaws and all has been tooken into consideration then I'd say I wish you luck and studding your male but you asked where to start and this is where to start and move on from....Hope I was of help...If not maybe somone eles could help you more.