Here's an ideas to help you remember what you've learned. It's a document I've created that helps you quickly recall everything you need to know.
Books and articles can be helpful, but how do you remember everything when you need it?
I've created a mind map called 'The Tree' where I attach notes I've made after leaning something new. I then allow it to branch off into the subjects I care about, giving me something that looks like a tree. This is extremely effective and if you're looking for a helpful app, I recommend iThoughts.
Just make sure that you include all the areas you need to focus on and that you can quickly recall the information. This process also gets you used to making clear and memorable notes that you'll quickly remember.