Hi. I am the wife of a US permanent resident and my husband filed for the spouse immigration case. it was a long procedure and i wrote my whole experience and about the whole process in 2 blogposts so that someone might get answers to questions they are looking for. I have tried to cover every detail in these two blogs but still if you have any kind of query, then feel free to ask me. i will try to answer it to the best of my knowledge. I hope this helps someone.
https://lizasworld1144.wixsite.com/musingsofadesigirl/post/us-spouse-immigration-type-f21-part-1-2
and
https://lizasworld1144.wixsite.com/musingsofadesigirl/post/us-spouse-immigration-type-f21-part-2-2