The cloud land is accessible one of two ways, either through the passage in the cave or climbing the bean stalk. Both methods require an item from the Gnome on the island. Depending on whether or not you guess the Gnome's name, you will get 3 beans or a key. The 3 beans are needed to grow the bean stalk. The key will open the door in the side of the mountain in E7.
Growing the bean stalk is the method worth the most points. You must first guess the Gnome's name (see information on Gnome's island for this). When successful, he will give you three beans. These beans can only be planted in the Clover Patch. When planted there, they will grow into a huge bean stalk. You can climb the bean stalk to the Cloud land. Be sure to save along the way—the bean stalk is not easy to climb. From experience, the best way to climb is to click near the bottom of the stalk, just a few pixels from the edge. That usually works. Corners are often difficult, but if you save often, it shouldn't be that bad. When you make it to the top of the bean stalk, walk directly to the right. Don't venture up or down or you will fall off the cloud. Once you are on green land, you are clear.
If you do not guess the Gnome's name correctly after three tries, he will give you a key instead of the beans. You can still complete the game just fine, but this method doesn't give you as high a score. The key will open the door in the mountain located in E7. This door will give you access to a cave with a series of walkways. It's a good idea to save while navigating these walkways as you can fall off, although they are significantly easier to go through than climbing the bean stalk. Also, the Dwarf can show up here and rob you, in which there are a few things that can be done. First, you can walk fast and hope he doesn't appear, which works fairly well (as long as you don't fall off!). Second, you can use the invisibility ring— the Dwarf can't see you if you're wearing the ring and therefore, can't rob you. Third, you can get protection from the fairy godmother (located in F2). Keep in mind that both of these methods don't protect you forever—you have about 60 seconds of protection with both. And, you still have to get back down.
Once you have made it to the top, you will be in an odd place with strange trees with multi-color leaves. On the map, the Giant is located in middle of the cloud land. From the bean stalk, that is three places to the east. From the cave, it's one place to the west.
There are 3 ways to deal with the Giant that will get you his Magic chest. One, you can shoot him with a slingshot, which is located in the far east corner of the cloud land. You will also need some pebbles (located next to the lake in A8) Upon entering the screen with the Giant, use the sling shot on him and knock him out. Two, you can run around in circles for about 20 seconds until the Giant gets tired of looking for you. Three, you can use the ring and stand around for 20 seconds invisible until the Giant gets tired of looking for you. When the Giant tires, he'll drop the chest. The game says to be quiet because the Giant is sleeping, but you don't actually need to worried about it—he won't wake back up. Although all methods work for getting the chest, getting him to fall asleep gives you the most points. Grab the sling shot anyway because you will get points for it.
After you have the chest, you can get back down using either the bean stalk (if that's how you got up) or the cave. You can still fall from both, so it is a good idea to save first.