ok im a complete novice and what do you mean put eggs under.cant i just buy a few finches i like,then if they breed they breed.im guessing this is a complicated hobby.
Well its all up to you realy dont plundge in at the deepend.
With the eggs again up to you, basicly its the same as you do with chicken eggs you can swap them under a broody bird so the british will then lay about 4 more this would increase your numbers the canary will rear the chicks as her own.
And when you buy any ritish birds make sure they have been ringed.