To help you type more accurately, your iPad includes the same feature found on iPhone and iPod touch, namely "Auto-Correction". When your iPad thinks that you have mistyped a word, it will automatically correct to the word it thinks you wanted to type instead. While very helpful, this feature can become a hindrance depending on the type of text you usually type on your iPad. This tutorial will explain how to turn off, or disable Auto-Correction on your iPad:
Click on the "Home" button, and navigate through Home screens to find the "Settings" icon, and tap on it.
Note that the Auto-Correction setting can be turned on or off at will, and very easily / quickly as you've just seen. Simply enable or disable it as needed, since in many cases your iPad can be quite helpful if you become familiar with its text replacement behavior (and the feature will save you quite a few keystrokes).