(BEFORE YOU BEGIN TO READ THIS, PLEASE NOTE THAT I DO NOT PLAY RANKED, BUT I MAIN THE JUNGLE, Not sure if this will change your decision making on what I am saying is reliable or not, but I figured you should know.) I am going to try and explain the "jungling process" from start to end, in any game, you will be able to see what your teammates have picked for champions, I follow a rule (unless you are first or second pick, this doesn't always work) if your team has 3 AD champions and a support (Yasuo, Zed, Caitlyn, and Sona or something, for example) it is best that you go ap (I like to use Amumu for most of my AP/tank needs, as well as strong cc). On the flipside, if you have 3 Ap champions and an ADC (Syndra, Swain, Sona, and Caitlyn) I highly recommend you take an AD jungler (Vi, Lee Sin, Kha'ziks, etc...). The last thing is, if the enemy picks something such as a Lee Sin (or any other stealth detection champ), then it is highly recommended that you DO NOT pick champions that use stealth (Kha'ziks, Rengar, Evelynn, etc...). Other small things you can use during champion select are also, does your team need a tank? do they lack damage? does your team have little cc? and relevant questions like that.
Now you are in game and have just bought your items (unless you are Warwick/Nunu/any other OP sustain champ), hunter's machete and 4 potions. What buff should you take first? It really depends on who you picked as a champ, and what side of the map you are on. Lets say that you chose Amumu, because your team needed tank stats/cc/AP. 95% of the time you should start at your blue buff, no matter what, the only time you would want to start at red is if you a confident you can start at red and d not lose mana after 2 camps, or if you get invaded at blue. Most champions can survive 3 camps (red, wraiths/wolves, and killing blue) without blue buff, if you are playing any of those champions, start at the bottom side buff (Purple side blue, blue side red) as Bottom lane gives the better leash 90% of the time. Most of the champions that can survive the 3 camps without blue include but are not limited to: Vi, Kha'zkis, Amumu (if smart), Lee sin, Rengar, Jarvan, basically every champ in the game can survive without blue, but some you have to be careful with. One of my friends asked me a question about the jungle a while ago, it was something like, "what time should the lanes stop leashing you?". If you started with the bottom side jungle, I recommend you send them off when the main monster is at 50% health or so, as you only need to damage it about 15% more before you can finish with smite. If your top/mid leashed, just ping after they do about 2 or 3 attacks, as they can't miss xp, and most of them only do 2 or 3 attacks anyways. If a champion that leashed you has a dot (twitch/darius) smite carefully, so they do not steal it on accident. When you want someone to back off of the buff when it is at 50%, don't do one measly "Danger" ping, Ping the hell out of the system with (default 'v' key)the back off ping. You don't want someone to think you just mispinged.
You have just finished you first jungle rotation, and you are looking at which lanes to gank(I am going to assume you started bottom side jungle). You see that your top laner has pushed the enemy up to their tower, but your midlaner is in the middle of the lane, and has frozen it smack dab in the center of the lane. Hopefully I got at least 2 braincells rubbing together there, and you decided to gank for your mid laner. (For some tips on ganking, I suggest this youtube video: https://www.youtube.com/watch?v=bOFvPUrAnTE ). The gank was successful, you burned the enemy's flash (Giving decent damage or burning a summoner makes a gank 'decent', getting a kill makes it 'good' getting a kill for your laner and assist for yourself makes it 'great', and killing the enemy [doesn't matter who gets the credit] and burning at least one summoner makes the gank 'amazing'. I can't type any more, outta characters, just look at guides, and practice a lot, add me too!- motomaster654