Read up
Definition 1 of 1
Pro Tip 1/3Scope of Research
Use 'read up' when intending to gain a broad understanding, not for in-depth expertise. 
To get the basics, I'll read up on quantum mechanics.
Pro Tip 2/3Preparatory Action
'Read up' implies action before engaging in a specific activity or discussion. 
Read up on the rules before joining the debate club.
Pro Tip 3/3Implies Initiative
Using 'read up' suggests a proactive effort to inform oneself without being told to do so. 
She read up on gardening to start her own vegetable patch.