Monash University in Australia hosts an academic English language self-study website, Learn HQ, with vast breadth and depth in reading, writing, speaking, listening, and grammar.
There are quick self-assessments to help you decide which resources to use.
I particularly like the treatment of academic reading. Here is an example exercise that gives the user an opportunity to practice locating the specific definition of important terminology in an academic book or paper.
What section of the Monash site did you find useful. Reply with your comment here!