It doesn't differ much from EU country to EU country (except your own country, where you are generally not covered by EU rules) because, as soon as you are making use of your right to freedom of movement, her right to join you is grounded in EU law.
Your wife needs a visa to enter the Schengen area (including Germany and the Netherlands) but if she is traveling with you or your child, she is covered by the EU freedom of movement. That means the visa should be free of charge and the requirements are minimal (she does not need to establish a valid purpose, financial means, etc. like other applicants but only to document her relationship with you, the fact that you are an EU citizen and that you would be travelling together).
Similarly, as long as you are living together, she can get a residence card quite easily. The most important condition to stay longer than 3 months is for you to have a job or enough money to be above the threshold to receive welfare. Your situation is very much like that described in US Citizen with EU Spouse who doesn't yet have a job (with the caveat that US citizens do not need a visa to enter, while your wife does) and Moving to Frankfurt with my Swedish wife, I am not EU citizen.
Importantly, your wife does not need to meet the more onerous requirements of “family reunification” visas for the family of a German citizen (like the language certificate) and she could apply for the residence card directly even if she entered on a short-stay visa. The-family-of-an-EU citizen route is therefore noticeably easier.