Well... That depends on what you are using Eclipse for. I will assume you are using it for Android development. If you are not, hopefully this will provide some insight on your application of Eclipse
Step 1. Download and Install the Java Development Kit (JDK) here.
Step 2. Download and install the Android SDK. Get it here
Step 3. Download Eclipse Classic Here
(as zip file)
Step 4. Extract Eclipse to a directory where you can remember.
Step 5. open eclipse.exe , then select Help > Install New Software....
Step 6. Click Add, in the top-right corner.
Step 7.In the Add Repository dialog that appears, enter "ADT Plugin" for theName and the following URL for the Location: "https://dl-ssl.google.com/android/eclipse/" Note: If you have trouble acquiring the plugin, try using "http" in the Location URL, instead of "https" (https is preferred for security reasons).
Step 8. Click OK.
Step 9. In the Available Software dialog, select the checkbox next to Developer Tools and click Next.
Step 10. In the next window, you'll see a list of the tools to be downloaded. Click Next.
Step 11. Read and accept the license agreements, then click Finish.
Step 12. When the installation completes, restart Eclipse.
p.s. When I downloaded the 64 bit edition of the JDK, the Android SDK could not seem to detect it. So, I then downloaded the 32 bit version of all software (JDK, SDK, and Eclipse) and had no problems since. Also, even if you are not using Eclipse for android dev, after following the above directions, you will still be able to use it for java development.