Reading the manual before starting to fly is the wrong way, in my opinion.
What benefit do I have in reading ~700 pages about HUD, TMS, CICU, ICP, DSMS, MFCD, WTF, OMG, and so on...
When I reach the next chapter, I forgot most of the stuff from the last one...
Start flying, with the manual in reach. practice flying, with the accourding chapter open.
Start understanding the instruments. Look at them one by one, referencing to the manual. Practice until you know what everything does.
So I prefer "RTFM while flying" instead of "RTFM before you fly"