Instructions
Find a tree. While standing by the tree, hold down the left mouse button to obtain wood or log. Cut down the entire trunk of the tree. Even if you have extra wood, it comes in handy for many crafting recipes.
Press "I" to open your inventory. This box on your screen shows your character on the left and a small four-squared crafting box -- your input box; your output box is on the right. Below that is your inventory space and below that is your toolbar. Click on the wood in the bottom part of your inventory screen and place it in one of the four input boxes. You need three pieces of wood to make the crafting table and five planks needed for the boat.
Create wood planks by collecting the planks once they have appeared in the output box. Each piece of wood creates four wood planks. By right-clicking on the planks, you will collect all that are available -- three pieces of wood would create 12 planks, which you can collect at once. Place them in your inventory below.
Create a crafting table. Click and drag the wooden planks up and fill in the input box of the crafting space. This will create a crafting table. Click on the table, which appears in the output box, and place it in the first space of your toolbar on the bottom of the inventory box. If you have any remaining planks in the crafting space, collect them and return them to your inventory.
Press "I" again to remove the inventory box and return you to the game. Find a place for your crafting table. If you are in your home, you may want to place it against a wall. Right-click, which should "throw" your crafting table down on the ground, making it usable.
Right-click on your crafting table. A screen similar to your inventory screen will pop up, but instead of your character and a four-squared crafting box, this screen includes a six-squared crafting input box with an output box. You will also have your inventory and toolbar below.
Left-click on your planks and distribute them. Click the planks and place each plank down by right-clicking. Leave the first row of your input box empty. Place a plank in the first and third columns of the second row and all three columns of the third row. A boat should appear in the output box. Click on the boat and place it in your toolbar. Hit "I" to exit the screen.
Find water. Right-click while selecting the boat in your toolbar to place the boat in the water. Right-click on the boat to ride. Accelerate the same as you would were you walking or swimming -- by holding down the "W" key.