PALS is a good class if taught right. It isn't an in depth patho type class, but it teaches you what you need to know to get them to definitive care. Also, I recommend taking it at a peds hospital if you can. Most PALS instructors have very little peds experience. Taking it at a peds center will make a huge difference in the quality.
STABLE is a good basic level class for neo. Again, not a patho overview, but it hits the basics. We used to teach these classes to the nurses at the referral EDs so they could get the basics taken care of while we flew out there to transfer the kiddo. Again, take it at a peds center if possible.
NRP is a notch above STABLE for neo. This is the card our transport team members had to carry. It is more in depth, and I wouldn't take it unless you have studied or have more than just a fleeting knowledge about neonates. You may not pass, and if you do, you likely just learned the test, and didn't tale away any substance. Again, take it at a peds center if possible.
For OB/GYN, short of doing a number of rotations in high risk L&D and getting exposure, there are not any classes to my knowledge that focus on that solely. A good understanding of the pathophysiology behind AP, PP, ectopic pregnancy, premature delivery, breach positions and corrective actions, tocolytics and uterine stimulants, and a few other details should give you a solid foundation for 90% of what you may encounter in the pre hospital setting. Monitoring and assessment of fetal heart tones shouldn't be overlooked either.
So, to wrap it all up, the card classes are about 10% of it. The other 90% comes from exposure, many many rotations with EXPERIENCED professionals (field trainers generally don't count for this, I'm talking people who have experience specializing in this kind of thing,) and lots of self study. If you have a peds specialty facility in your area, get in touch with someone from their transport team or ED, and ask about nursing con ed and possibly even grand rounds to see if it is ok for you to sit in. Since you would be auditing these lectures and not taking a seat, they may likely be free. However, without a good base of knowledge, they may be worthless.
Just my opinion on the matter...