Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Gain Gold, Ward, Take objectives, Ward more
At the start of the game you will have to get some gold, quick. Look for easy ganks, but don't take huge risks. If you can not gank easily, try hard farming instead. This is for when you lane has low damage, no cc or are pushing too hard. Now that you have gained some gold, buy your core items.
Now that you have your sightstone and bloodrazor start warding and setting up objectives. This is also about the time you should get a red trinket. If you have vision in the enemies jungle, and makes sure they don't have vision on dragon, you can easily solo it. Your team doesn't even need to join you. This makes them more happy, and the enemies more confused.
You should invest in pink wards often. Try buying it on your first back. Whenever your pink is cleared, you should buy a new one. You should also buy a new one when you can start gettting more agressive wards.
Keep up the wards, gain some objectives, and then win the game. Have fun and remember, don't be selfish. This build is all about vision control and objectives, not solo kills or damage.