The website https://transequality.org has really great, comprehensive information, which covers many different situations. It is, however, a bit complicated and dense.
We distilled this information into this step-by-step recipe, with our specific case (and a few tweaks from hindsight), which is what we wish we had starting out.
If your case is similar, this may work for you:
- we're his biological parents
- we're still married and all live together