Start here
If you are at the very beginning, three guides answer most of what you need before a first conversation.
Procedure and paperwork
For those already in the process, or about to file.
A note on using any of this
These guides describe the general position. Whether they apply to you depends on facts we have not seen: which statute your marriage falls under, what has already been filed, what was agreed and by whom.
Nothing here is legal advice, and reading it does not create a lawyer–client relationship. Where the stakes are significant (children, property, a criminal complaint), get advice on your own facts before acting.