This screen lets you set various QDK options, including what type of room descriptions (Standard, Words Only or Script) to use by default.
Turn on AutoSave and QDK will save your game file regularly. This is useful if you decide you need to go back to a previous version, or if you forget to save regularly.
This screen lets you specify where the QCompile and QuestNet Server files are. By default, QDK looks in the same directory that it's installed in, which is usually where these files are.