Welcome to DB!
Modern Day Chemicals:
Whey Proteins that actually mix well with water and taste great
Fish Oil as part of the EFA Complex for helping you to lose weight
Multi-Vitamins
Creatine (V12, regular creatine and other transports)
NO2 type supplements for a pump (like L Arginine)
Newer Training:
Max-OT
German Volume Training
AtoZ All Star Fitness ebook
Jeff Anderson's Optimum Anabolics Program
A less is more approach seems to be the latest rage. More intensity but less time in the gym as to avoid the over-training. Long gone are the days of 7 days a week, 4 hrs in the gym. It seems with the newer training programs things are safer and more intense.
One thing hasn't changed. The basics. Most good programs still incorporate the basics like squats, benching, curls and pull-ups.
And of course a bigger change has been the overall effort to encourage people to gain a better understanding of nutrition.
Take what you knew in the 1970's, take that hardcore intensity, apply some new age programs a little bit of nutrition and you will be back in share in no time.
Most important of all: Take it slow. After 20 years you want to get back into the routine. Not go all out, get too sore and quit. So start off simple, read some of the posts on this forum, check out the various ebooks and posts on nutrition and get off to a nice and easy start. I'd like to know that you'll have regular workouts for the next 20 years from here on out!