Howdy, Barley. 

If I may suggest a place to start, http://www.missing-lynx.com/articles/figures/mbface/mbface.htm  Bannerman's tutorials helped me refine my skills and added some techniques to my tool chest quite a few years ago.  You can check on several of his articles and others, here: http://www.missing-lynx.com/articles/articles_figures.htm  There's a few on YT, but not many.  Oils are not too popular, acrylics being the go-to choice.  but honestly, there's quite a few of us oilers out there.  Not everyone has crossed over to the "dark side."

But get rid of those cheap oils in your drawer, for starters.  They won't do you any good, if you're serious.  I would suggest Windsor and Newton.  One tube will last you a lifetime, and get some quality brushes.  Not super expensive ones, just decent ones that can handle the beating the oils will put them thru.  I smoke through a few with every set of figures I work.  I just happens that way.

I use acrylics for the base tones, oils blended over that.  It's all about blending and feathering colors together.

Hope that helps, Barley.  Cheers, Ski.