So you want to counterjungle?
Then you should know these basic differences between goldflow in the jungle and lanes.
Firstly, while each minion in the lane is worth basically the same as one another, it's a different story in the jungle. Each camp can be split into two types of monsters: The "big one" and the "small ones". While the small ones are easy to kill, and not really worth the effort at all, the "Big Ones" are worth triple to gold and experience of the small ones, and are generally the most important ones to do.
Secondly, in lane the gold comes to you. You don't have to wait long before another wave of gold walks up to you and basically gives itself to you. However, in the jungle you have to walk to each camp to get it, in other words, in lane the gold comes to you, but in the jungle you have to go to the gold.
Finally, spawn timers in the jungler are different. Each 30 seconds, a wave of minions is spawn from both nexii. However, in the jungle, the camps are only respawned if it is completely cleared, and a certain amount of time has passed. 50 seconds for wraiths, 60 seconds for wolves and golems, and 5 min.s for the big buffs. MEMORIZE THIS.
What can you take from these three points? That if you take the big monsters of each camp... you can waste the enemy's time by taking half of his gold and experience... and slow down his future jungle because his small monsters are still there.
This is the basics of counterjungling.