If you still want to use the full Android SDK (as I've changed my guide to use Mini SDK), here is how you install it (for Windows OSes only):
This guide will assume you're running Windows XP or later. But, what software you download and what directory the Android SDK will install itself into will depend upon if you have a 32-bit or 64-Bit version of Windows. How do you tell? Right click on My Computer, or open your Start Menu and right click on My Computer (or 'Computer' as Win 7 refers to it) and click on Properties. In the middle of the page, it will tell you if you're running a 32-Bit or 64-Bit version of windows.
First, you need to download a lot of software. So here are the download links:
1) The Java Development Kit (JDK) - Install this first, the Android SDK will not let you continue if it does not detect a JDK.
a)
JDK for Windows 32-Bit systems
b)
JDK for Windows 64-Bit systems
2)
Android SDK Installer
Now, how to configure the Android SDK. After installing the Android SDK, it'll prompt you to start the SDK Manager. Yes, you want to start it. Check 'Tools' at the top. Also check Android 2.3.3 (API 10) and then Install XX packages. Mine said 27 packages, yours may be different. Also, ignore that it's calling it Android 2.3.3 and you're likely on Android 2.3.4. Android 2.3.4 uses the same APIs as Android 2.3.3, so it's fine. That will take a little bit to download and install. Once it is done, you can use fastboot and ADB.
*Note, now that we're on Android 4.0, you can use the Android 4.0 API instead of the Android 2.3.3 API. I don't think either are truly necessary, but it wouldn't hurt to grab both or none of them.
If you have the full Android SDK and 32-Bit Windows, your platform-tools directory will be here:
Code:
cd C:\Program Files\Android\android-sdk\platform-tools
If you have the full Android SDK and 64-Bit Windows, your platform-tools directory will be here:
Code:
cd C:\Program Files (x86)\Android\android-sdk\platform-tools