All you have to do is go into rooms and you should find them. Some times the monkeys you find lead you to the other ones that are trapped. My advice is to find 5 monkeys then go get the boomerang. Once you get the boomerang getting all the other monkeys are easier.
If the above is to complicated then just find the compass and all the monkeys will appear on the map.
In Twilight Princess, the only monkey whose name is given is the forest temple boss monkey - his name is Ook.
collect all the monkeys then defeat the flower boss
get the boomerang.
The big key
As you go through the first temple (forest), you will gather more and more monkeys.
After you complete the Forest Temple the twilight is no longer in that region and Link must travel to the next region of Hyrule to rid it of the twilight
8 in all, including the four you have to find before the mini-boss
as soon as you defeat the Minny Boss in the Forest Temple you get the boomerang
See there are monkeys scattered throughout the dungeon once you get like 4 then they help you across
All you have to do is go into rooms and you should find them. Some times the monkeys you find lead you to the other ones that are trapped. My advice is to find 5 monkeys then go get the boomerang. Once you get the boomerang getting all the other monkeys are easier. If the above is to complicated then just find the compass and all the monkeys will appear on the map.
Mainly by usingyour boomerang you havereceived in the Forest temple by beating the monkey. (miniboss)
It's in the Forest Temple (1st Dungeon. You need to beet Ook to get it though.