I don't, most explanations don't work as well as seeing the mechanic.
I read the Journal simply because it is a resource and gives me a little extra insight as to what to expect.
I just go to icy-veins and look up raid resources, cick on the boss and watch the video for lfr purposes. When my raid decides to tackle a boss I read through the individual abilities on that same page and let my raid know the finer points. I am usually the one spitting out key mechanics at the beginning of LFR fights to increase the chance of one shotting the boss.
I don't read the journal, I tend to be one step slackier and check sites like icyveins or the like for tactics, particularly when it's my week to handle the raid. I find reading about the encounter and the various abilities a lot easier to comprehend and conversely develop or adapt tactics through, rather than watching a video. Generally don't do this for LFR altho it has happened if I've come across an encounter where it isn't obvious what to do. I read up more now than I used to do.