Hello.
I am going to tell you how to grow apple trees from seed. This is a lot more complicated than just throwing a few seeds in the ground, but with my help I can show you how.

Step 1: Materials Needed

You will need:
An apple
Compost
Pots
Paper towel
plastic bag
Knife
Later On:
Grafting tape or Cling film
Grafting Wax or Masking tape

Step 2: Getting the Seeds

Now, Carefully cut down the middle of an apple and take out the seeds. You may need a few apples always remember on average only 30% of your seeds will germinate.

Step 3: Getting the Seeds to Germinate

Now we need to get our or paper towel and wrap our seeds in them. Wet the paper towel and put it in the plastic bag. Make sure the plastic bag is sealed tight, and put it in the fridge. Your seeds should take about a month to germinate but check every few weeks and wet again if dry. Your seeds will start to have little white sprouts coming out of them soon enough thats when you know there ready for planting.

Step 4: Planting Seeds

Once the seeds have germinated just drop them into any pots about 1 - 2" deep and cover in good compost. Then just watch them grow.

Step 5: The Most Important Step: Grafting

This step is vital or you apple trees will not produce any apples.
First wait until your apple trees are about 30-60 cm high.(Like in picture)
Now there are many different methods of grafting apple trees but the one I use and find most helpful is the "Whip and Tongue" graft.

Use pictures to help with the graft. Pictures used on random pieces of wood for an example.
Firstly you get a piece of wood (Scion wood) from the variety of apple you want.
Then you cut down at an angle on wood.
Now make an identical cut on the apple tree.
Then cut downwards on the sliced wood. Do this on both tree and scion wood.
Then push together and wrap with cling film and then masking tape.
Done.

Step 6: Watch for Results Some Will Be Unsuccessful.

Watch closely for results if you graft is growing leaves then it is successful if it isn't it probably isn't successful, After 1-3 months take off the grafting tape.