TL;DR:
You give the seeds to Hestu. He can be found at:
- 1st location is on the way to Kakariko Village in West Necluda.
- 2nd location is after completing his side quest and giving him enough Korok Seeds, he will attempt to return home but will get lost. It appears his second location seems to alter for players. Various sources, state he can be found at the Wetlands Stable, Woodlands Stable, or Riverside Stable next. All of these stables are along the Hylia River, which is what Hestu said he would follow to get back to his home. It's unclear if he will visit one, two, or all of these locations before making it to his third. Nonetheless, here are some sources showing and discussing his possible second location(s):
- This linked video for his second location shows where he will be for the Riverside Stable location.
- This map shows he can be present at the Woodlands Stable.
- Various sources also suggest the Wetland Stable, such as here, here, this answer to another question, and the Wiki for Hestu.
It's possible he may skip this location if you give him enough seeds at the first location and will progress to Korok Forest (the third location). According to IGN, he will perform 6 upgrades here, but other sources say 5. After that, he will move.
- 3rd location is in Korok Village/Forest. Currently, this is believed to be his final location (as it is his home). To reach it, you must go through the Lost Woods.
(Main Source)
According to the Wiki for the seeds, you give them to the Korok Hestu.
When Link is given one, he is asked to return it to the Korok Hestu.
You will also need to get him his Maracas as well before you get a reward.
If Link returns him the missing Maracas and gives him a Korok Seed, Hestu will add one slot to either his Weapon, Bow, or Shield stashes.
Hestu moves after you give him a certain amount of seeds. At the moment, there is currently three locations that I could find. This link contains some of them.
Hestu's first location is on the way to Kakariko Village. This is where you will get his side quest for finding his Maracas.
After completing his side quest for finding his Maracas and giving him a certain amount of seeds (possibly two), he will attempt to go back to his home, but will get lost. His next location will be either next to a Shrine to the north west of Batrea Lake near the Riverside Stable, the Woodland Stable, or the Wetland Stable. It is unclear at this time if he will stop at all of these locations, or just one of them before making his way to the third location. Also, if you gave him enough seeds at his first location, he may skip this location and proceed to the third.
Hestu's third location is within Korok Village. To reach it, you need to go through the Lost Woods, which appears to be a navigational challenge. This is also currently believed to be his final location since it is his home and according to this website, he takes permanent residence here:
...finally taking permanent residence within the Korok Forest.
The thing you need to realize is that the sensor isn't telling you that you are near a target, only that you're merely moving in the direction of the target. The better the signal, the more it is directly ahead of you. So if it's beeping at full strength, that means you should start walking straight ahead. If it's not at full but some bars, you should start turning until you could get a better signal. If you have nothing at all, then the target is nowhere near you at all. If you're standing still, then you won't get any feedback, only that the target is somewhere in the area or none at all.
So as you're moving about, keep walking straight as long as the signal is full. If it isn't course correct until it is. You'll eventually reach your target as long as you're able to recognize that you've found it.
there are no targets in the area and you should go elsewhere
a target is in the area but you're not moving or the target is behind you
you are walking toward the target so keep moving straight
Best Answer
Best of luck grabbing those last couple seeds, as you have no doubt noticed there are a lot of them.
I found that this interactive map is quite useful as you can filter it to show the location of all the seeds. Additionally when you click on the little seed icon, there is a small info window that pops up with a small photo and descriptor of that specific seed.
Additionally, in those little info windows there is the option to mark the seeds as completed/not completed. Then you can use the little gear in the top left corner to hide "completed" seeds, so you can track your progress as you go.