Hi Jay
Like you I was a dedicated "oiler" for decades, but I switched to Vallejo acrylics a couple of years ago, and I'm very glad I did.
Stephen is right, the best way to learn to use acrylics is to experiment.
I have found that the key to acrylics is to keep your paint very dilute and build up the colour by applying multiple coats of paint (almost like washes) rather than try to cover the surface with one or two thick coats of paint. This technique requires a lot of patience, but it produces very satisfying results.
The main difference between the two paint mediums is the drying time. I find I tend to paint faster in acrylics because I don't have to wait as long for the paint to dry
, although this is balanced by the fact that I usually apply several more coats of paint when using acylics than I would if I was painting in oils.
Books may be useful guides, but you wont learn how to paint from them. The only way you'll learn to paint in acrylics is to practice your painting using acrylics, preferably on some crappy old figures, and simply experiment with different techniques and styles.
I still use oils, enamels and acylics together, and I find that certain types of paints tend to be better than others for different tasks.
I still like to give skin and wood surfaces a touch of oils to add a natural sheen (I find acylics leave skin looking too flat and unnatural looking), I prefer to use enamels for metalic surfaces, and I think acylics are best for uniforms and other surfaces that require a dead flat finish. Each to his own!!
So long as you are having fun and getting good results, it really doesn't matter whether you are following the "correct technique" laid down in a book.
Cheers