First you make a enchantment table, 4 obsidian, 2 diamonds, and 1 book. Then, you take any tool, put it in the enchanting table. You keep putting it in and out until you find a enchantment that has atleast 2 lines, and click it, if you have enought exp. You can gain exp by killing mobs. If you want a higher enchantment, put some bookshelves around the enchanting table. They have to be 2 blocks away. Put torches around the enchanting table to make the levels a little smaller. And that's how you get a good enchantment.