First off,  let me start by saying I have just recently learned the importance of good bankroll management.  Lets just say that recently I have been reduced to nothing.  Not through "bad" luck but because of bankroll management (or lack thereof).   Not to say that "bad" luck didnt have something to do with it, but consequencialy,  my bankroll couldnt stand up to the varience.  There are numerous ideas involved with bankroll management, all of which have been discussed extensively online.  For that reason I would only like to focus on what I belive to be essential to maintaining and growing your bankroll.  Varience.  Varience, varience, varience.  Learn everything there is to know about varience,  what it is,  what it means,  which games offer high/low varience.  If you learn ONE thing about varience, make it this...   winning over the short term is luck,  winning over the long term is skill.  This is because varience dictates (depending on the game)  how high/low your bankroll will "vary" before you can expect to see a "real" depiction of what you have won or lost.  In lamens terms this means that even though you won $1000 in 3 consecutive sessions,  do not expect to win $1000 everytime you play.  This may seem obvious, but even the seasoned pro can find themselves expecting to win more than they really should.  Varience dictates that for three winning sessions, producing $3000 in earning,  that one should expect to lose around $2500 or so back.  Of course this is just an example, with winnings and losings expressed as variables given value.  The player not thinking about variance thinks they won $3000 during 3 sessions, then lost $2500 during another 3 sessions.  The player thinking about variance understands that they actually won $500 during 6 sessions. $500/6 sessions = +$83.33 won each session.  This is varience.  The more hands you play, the more defined the varience is for a given game and a given play style, regardless of luck.  Remember, luck = winning in the short run,  skill = winning over the long haul.  I hope this has helped a few of you think more of the long haul and less of the short run.  We all have "bad" luck, which may last a few sessions, a few weeks, or even a few months...  but taking varience into account,  analysing your play (good or bad), and finding holes in your game where you can save a blind or two will all equal a better understanding of bankroll management.  Its up to you to decide whether poker is profitable enough to justify the time spent playing,  just make sure that you are always thinking about varience, and that even though you won big today, do not use that as a reason to play beyond your bankroll because if you do, its not a matter of how your bankroll will be destroyed, its a matter of when.