The problem with SOAP notes for ob/gyn is they depend on what you're doing. a labor check is different than a postpartum note, different than a post op note...I know medfools has a generic one, but the best bet is to get the info from your resident about the template they want you to follow. No one will fault you for asking.
I used First Aid for the Wards. Unfortunately, it's not a site but it's a good book. It's best for exactly what you're looking for - a format for notes for each rotation. For each of my 3rd year rotations, I bought a small notebook and put important notes in the first few pages. I copied examples of the SOAP notes for Ob/Gyn in that section.