In Minecraft there are four tools and making them all out of wood is quickest though any refined ore will work as well.
Collect around 16 blocks of wood from trees, create a crafting table. With that table, produce 8 Wooden Sticks and 9 Wooden Planks (or 9 refined Ores). Then craft an Axe, Hoe, Pickaxe and a Shovel. I've included Minecraft wiki pages for each below.
http://www.minecraftwiki.net/wiki/Axe http://www.minecraftwiki.net/wiki/Hoe http://www.minecraftwiki.net/wiki/Pickaxehttp://www.minecraftwiki.net/wiki/Shovel