i recently began a program called "starting strentgh" by Mark Rippetoe. He has tons of videos on youtube.
but it even has a VERY nice app as well.
It takes ALL the guess work out of training. Its basically the principles of understanding the bench press, squat, overhead press, and deadlift. You slowly increase the weight and the app calculates it for you. I'm only a week in and i can tell its working b/c had i tried to do these exercises back in the day, i would've been sore af, but i can feel the small incremental strength already.
You will be tempted to jump ahead of the program, but its best you follow it the way its designed to avoid injury. It keeps tracks of your lifts and everything and even includes excerpts from his book and videos to show you how to do the lifts, but you can always go to youtube. He has a wealth of knowledge.
the app is 9.99 but worth every penny, but whats 9.99 mean to your health? I say its worth it.
I'll be posting some progress in about another 3 weeks which will make me one month in.