Wow, good for you!  Most people get all nervous when they see 'endocrine.'  Pediatric Endocrinology is a specialty area of nursing just like any other area.  Unless you're going into advance practice, just as NP, it doesn't need an advanced degree beyond getting your RN.  The best thing to do is probably find a pediatric hospital or a pediatric endocrinology MD practice in your area and give them a call.  Most people love talking about what they do, and I'm sure you'll be able to find several people in that field who would be thrilled to tell you all about it.  They might even let you shadow them for a day or two to see what it's like first hand!  Then if you decide it's the field for you, you already have a contact if you decide to apply for a job there.  After all, who would YOU want to hire...the nurse who showed and interest and made an effort to learn more and get to know the practice...or the nurse who just turned in her resume?  They would want the nurse that they already know is motivated!

The types of disorders you would probably be seeing in the kids would be any of the endocrine disorders that you study in nursing school...too much/too little growth hormone, Diabetes, that sort of thing. 

If it's just a matter of you loving kids, you can just do pediatrics in general, too.  That might be good to start out with.  I am a pediatric nurse, and I got my start in the Operating room.  Now I do after hourse phone triage for pediatric offices.  The advantages of working with kids is that they surprise you all the time...they are so resiliant!  Even the ones who are really sick, or have a chronic or terminal illness just want to play with you and be kids.  Of course, that is also a disadvantage...some people find it very difficult to work with sick kids because it makes it more difficult to separate yourself from the job.  And remember, you'll be the one giving them their shots!

Anyway, hope this helps!

It's impossible to say what the starting salary is because it will depend a lot on where you live, what the going rate is for nurses.  I started in a pediatric OR immediately out of school, so as a new grad RN, I was getting $20-$21 base rate.  If you're working in the hospital, there's usually extra pay for things like working nights, evening, weekends, or doing on-call hours.  The best thing to do would be to cal lthe nurse recruiter (or talk to some recent nursing grads) and find out what the going rate for nurses is in your area.