Boomer babysitter for grandkids. I have the 1980 something nelson peds book. Is that still useful?

No tUseful in 2015. It is not useful now as lot as changed in Pediatrics in 35 years.
Pediatric Informatio. It is always better to use uodated information. There are very good websites now a days for the latest authentic Patient information depending on the problem. Some information has not changed. But always double check with updated information before making any decisions. This is a general professional advice limited to USA patients based on information provided.
Nelson is useful. Dr. Waldo E Nelson was the chief at St. Christopher's hospital for children. The hospital was founded in1875. He used the patients found in Philadelphia to describe the diseases in the text book. His text book remains the gold standard and most diseases have not changed dramatically. The Internet has many useful but inaccurate information. The textbook can serve as an accurate resource. .
Nelson Textbook. Useful for what? As the grandfather, you are not responsible for being a pediatrician. You are responsible for keeping the grandchildren safe and fed. You are responsible for having the pediatrician's phone number. The book, by the way, has a lot of useful information about typical childhood illnesses, but most of the treatments are out of date.
Nelson's . From a general standpoint probably yes. It has been updated quite a few times since then. The aap has a lot of good info on their website that may help. Here's the link: www.Healthychildren.Org.
No. Nelson's pediatrics is highly technical and useless to you. Use common sense and loving care-----all that is necessary!