So you want to try cuttlefish?

Go to http://ci.android.com/
Enter a branch name. Start with aosp-master if you don‘t know what you’re looking for
Navigate to aosp_cf_x86_phone and click on userdebug for the latest build
Click on Artifacts
Scroll down to the OTA images. These packages look like aosp_cf_x86_phone-img-xxxxxx.zip -- it will always have img in the name. Download this file
Scroll down to cvd-host_package.tar.gz. You should always download a host package from the same build as your images.
On your local system, combine the packages:
$ mkdir cf $ cd cf $ tar xvf /path/to/cvd-host_package.tar.gz $ unzip /path/to/aosp_cf_x86_phone-img-xxxxxx.zip
Launch cuttlefish with:
$ HOME=$PWD ./bin/launch_cvd
Stop cuttlefish with:
$ HOME=$PWD ./bin/stop_cvd

So you want to debug cuttlefish?

You can use adb to debug it, just like a physical device:

$ ./bin/adb -e shell

You can use the TightVNC JViewer. Once you have downloaded the TightVNC Java Viewer JAR in a ZIP archive, run it with

$ java -jar tightvnc-jviewer.jar -ScalingFactor=50 -Tunneling=no -host=localhost -port=6444

Click “Connect” and you should see a lock screen!