If you want to sell the milk for human consumption you will be drowning in paperwork... soapmaking is one route (but it doesn't use up loads of milk), other options are to feed a couple of weaners with the milk (and on reduced pig food concentrates), and so produce good pork (which you may find you can sell if going through a butcher). You could also feed bottle lambs (although this usually happens when you need most of your own goatsmilk for the goat kids) and taking in lambs from other farms where they may not have had an ideal start to life may just bring more problems than any profit, but it is an opportunity (or you can sell to a farmer nearby).
We only produce milk for the house, but invested in a cream separator, so now also make all our own butter, cream and ice cream, I make cheese for us, feed a couple of weaners on excess milk and at the time we have lambs any triplets/orphans will be on goatsmilk too... so not making money directly from the goats, but they save us money on a lot of things.